| I&B | Information and Broadcasting |
| I18N | Internationalization |
| I3A | International Imaging Industry Association |
| I3A | Installation Information Infrastructure Architecture |
| I3A | Indole-3-Acetonitrile |
| IA | Iowa |
| ia | inter alia |
| ia | Interlingua |
| IA | Information Architecture |
| IA | Information Assurance |
| IA | Internet Archive |
| IA | Indian Army |
| IA | Inflammatory Arthritis |
| IA | Intelligent Agent |
| IA | Intel Architecture |
| IA | International Academy |
| IA | Iraqi Army |
| IA | Inuit Ataqatigiit |
| IA | Iraqi Airways |
| IA | Intelligence Amplification |
| IA | Integrated Amplifier |
| IA | I Agree |
| IA | Indian Airlines |
| IA | Intact America |
| IA | International Artists |
| IA | Indiana Academy |
| IA | InstallAnywhere |
| IA | Industrial Archaeology |
| IA | Internet Archaeology |
| IA | Institute of Archaeology |
| IAA | Indole 3 Acetic Acid |
| IAA | Internationale Automobil-Ausstellung |
| IAA | Israel Antiquities Authority |
| IAA | Information Affairs Authority |
| IAA | International Actuarial Association |
| IAA | Indianapolis Airport Authority |
| IAA | Israel Airports Authority |
| IAA | Irish Aviation Authority |
| IAA | International Academy of Astronautics |
| IAA | Independent Ambulance Association |
| IAA | International Academy of Architecture |
| IaaS | Infrastructure as a Service |
| IaaS | Information as a Service |
| IaaS | Integration as a Service |
| IAAS | Institute of Agriculture and Animal Science |
| IAAS | International Association of students in Agricultural and related Sciences |
| IAAS | International Association for Ambulatory Surgery |
| IAAS | Indian Audit and Accounts Service |
| IAAS | Institute of Auctioneers and Appraisers in Scotland |
| IAAS | Incorporated Association of Architects and Surveyors |
| IAB | Internet Architecture Board |
| IAB | Interactive Advertising Bureau |
| IAB | McConnell Air Force Base |
| IABA | Institute for Applied Behavior Analysis |
| IABA | Irish Athletic Boxing Association |
| IABA | International Association of Black Actuaries |
| IABA | Iranian American Bar Association |
| IABA | Islamic Ahlul Bayt Association |
| IABA | Interior Alaska Building Association |
| IAEA | International Atomic Energy Agency |
| IAEA | Independent Administration of Estate Act |
| IAEA | Institute Of Automobile Engineer Assessors |
| IAF | Indian Air Force |
| IAF | Israeli Air Force |
| IAG | Insurance Australia Group |
| IAG | International Association of Geodesy |
| IAG | Niagara Falls International Airport |
| IAG | International Association of Geomorphologists |
| IAmA | I am a |
| IAMA | Iranian American Medical Association |
| IAMA | International Artist Managers’ Association |
| IAMA | International Automotive Media Awards |
| IAMA | International Association for Microanalysis |
| IAMAI | Internet & Mobile Association of India |
| IANA | Internet Assigned Numbers Authority |
| IANA | International Academic Nursing Alliance |
| IANS | Indo-Asian News Service |
| IAO | Information Awareness Office |
| IAO | International Accreditation Organization |
| IAO | International Astronomy Olympiad |
| IAP | In-App Purchase |
| IAP | Indian Academy of Pediatrics |
| IAP | Internet Access Provider |
| IAP | Inhibitors of Apoptosis |
| IARC | International Agency for Research on Cancer |
| IARC | International Age Rating Coalition |
| IARC | International Arctic Research Center |
| IARC | Individual Aircraft Record Card |
| IARC | International Aerial Robotics Competition |
| IARC | Indian Arts Research Center |
| IARC | Israel Amateur Radio Club |
| IAS | Indian Administrative Service |
| IAS | International Accounting Standards |
| IAS | Internal Audit Service |
| IAS | Institute for Advanced Study |
| IAS | Indian Academy of Sciences |
| IAS | IEEE Industrial Applications Society |
| IAS | International AIDS Society |
| IAS | Internal Anal Sphincter |
| IAS | International Association of Sufism |
| IAS | Indicated Airspeed |
| IAS | Internet Authentication Service |
| iAS | Internet Application Server |
| IAS | International American School of Warsaw |
| IAS | Islamic Academy of Sciences |
| IAS | Institute of Agricultural Sciences |
| IAS | Institute for Advanced Study |
| IAS | Institute of Advanced Study |
| IAS | Institute for Anarchist Studies |
| IAS | Izquierda Asturiana |
| IAS | Institut Aéronautique et Spatial |
| IAS | Iași International Airport |
| IAS | Instituto Ayrton Senna |
| IAS | Investment Analysts Society |
| IAS | Immunisation Awareness Society |
| IAS | Institute of the Aeronautical Sciences |
| IAS | International All Sports |
| IAS | Image Analysis & Stereology |
| IAS | Iowa Archeological Society |
| IAS | Iranian Arachnological Society |
| IAST | International Alphabet of Sanskrit Transliteration |
| IAST | Ideal Adsorbed Solution Theory |
| IAST | Institute of Applied Science and Technology |
| IATA | International Air Transport Association |
| IATA | International Amateur Theatre Association |
| IAU | International Astronomical Union |
| IAU | International Association of Universities |
| IAU | Islamic Azad University |
| IAU | International Association of Ultrarunners |
| IB | International Baccalaureate |
| IB | Intelligence Bureau |
| IB | Instituto Balseiro |
| IB | Intelligence Bureau |
| iB | Ikonboard |
| IBA | International Bar Association |
| IBA | Indian Banks Association |
| IBA | Institute of Business Administration |
| IBA | Institute of Business Administration |
| IBA | International Bartenders Association |
| IBA | Important Bird Area |
| IBA | Indole-3-Butyric Acid |
| IBA | Independent Broadcasting Authority |
| IBA | Institute of Business Administration |
| IBA | Institute of Business Administration |
| IBA | Internationale Bauausstellung |
| IBA | Ion Beam Analysis |
| IBA | IsoButyl Alcohol |
| IBA | Institute of Business Administration |
| IBA | International Bank of Azerbaijan |
| IBA | International Bear Association |
| IBA | International Bodyboarding Association |
| IBA | International Boxing Association |
| IBA | Ion Beam Applications |
| IBA | Iron Butt Association |
| IBA | Israel Broadcasting Authority |
| IBA | Interest-Based Advertising |
| IBA | Incinerator Bottom Ash |
| IBA | InfiniBand Architecture |
| IBA | Interceptor Body Armor |
| IBA | International Basketball Association |
| IBA | International Bryozoology Association |
| iBA | iBooks Author |
| IBA | International Bank of Asia |
| IBA | International Buddhist Academy |
| IBBM | Iron Body, Bronze Mounted |
| IBBM | Institute of Bankers Malaysia |
| IBEF | India Brand Equity Foundation |
| IBEF | International Bitumen Emulsion Federation |
| IBEF | International Business Exchange Forum |
| IBEW | International Brotherhood of Electrical Workers |
| ibibo | iBuild, iBond |
| IBM | International Business Machines |
| IBM | Inclusion Body Myositis |
| IBM | Interacting Boson Model |
| IBM | International Business Management |
| IBM | International Brotherhood of Magicians |
| IBM | Izu-Bonin-Mariana |
| IBNR | Incurred But Not Reported |
| IBPS | Institute of Banking Personnel Selection |
| IBPS | International Buddhist Progress Society |
| IBPS | Intelligent Battery and Power System |
| IBPS | Inter Bank Payment System |
| IBRD | International Bank for Reconstruction and Development |
| IBS | Irritable Bowel Syndrome |
| IBS | Internet Broadcasting Systems |
| IBS | Institute of Broadcast Sound |
| IBS | International Bible Society |
| IBS | Institute of Bangladesh Studies |
| IC | Integrated Circuit |
| IC | InterCity |
| IC | Interchangeable Core |
| Ic | Collector current |
| IC | Interstitial Cystitis |
| IC | Ion Chromatography |
| IC | International College |
| IC | Incident Commander |
| IC | Internal Control |
| IC | Inferior Colliculus |
| IC | Irreducible Complexity |
| IC | Inspiratory Capacity |
| IC | Ithaca College |
| IC | Identity Card |
| IC | Indifference Curve |
| IC | Information Coefficient |
| IC | Index of Coincidence |
| IC | Interconnection |
| IC | Index Catalogue |
| IC | Intermittent Catheterisation |
| IC | Ionization Chamber |
| IC | Isolation Condenser |
| IC | Illinois College |
| IC | Imperial College |
| IC | Illinois Central Railroad |
| IC | Indian Airlines |
| ic | in casu |
| IC | International Canoe |
| IC | Institute of Charity |
| IC | Interactive C |
| IC | Integrated Coach |
| ICA | Independent Component Analysis |
| ICA | Institute of Contemporary Arts |
| ICA | International Co-operative Alliance |
| ICA | Independent Computing Architecture |
| ICA | Institute of Computer Accountants |
| ICA | Immigration and Checkpoints Authority |
| ICA | Icabaru Airport |
| ICA | Isotropically Conductive Adhesive |
| ICA | Imputation Credit Account |
| ICA | International Criminologists Association |
| ICA | Interstitial Cystitis Association |
| ICA | Institute of Contemporary Art |
| ICACCI | International Conference on Advances in Computing, Communications and Informatics |
| ICAEW | Institute of Chartered Accountants in England and Wales |
| ICAI | Institute of Chartered Accountants of India |
| ICAI | Institute of Cost Accountants of India |
| ICAI | Institute of Chartered Accountants in Ireland |
| ICAI | Intelligent Computer-Aided Instruction |
| ICAN | International Cesarean Awareness Network |
| ICAN | Institute of Chartered Accountants of Nigeria |
| ICANN | Internet Corporation for Assigned Names and Numbers |
| ICAO | International Civil Aviation Organization |
| ICAR | Indian Council of Agricultural Research |
| ICAR | International Centre for Asset Recovery |
| ICAR | International Congress on Animal Reproduction |
| ICAT | International Centre for Automotive Technology |
| ICAT | International Cat Agility Tournaments |
| ICAT | International Conference on Artificial Reality and Telexistence |
| ICBC | Industrial and Commercial Bank of China |
| ICBC | Insurance Corporation of British Columbia |
| ICBM | Intercontinental Ballistic Missile |
| ICBM | International Consortium for Brain Mapping |
| ICBM | Independent Community Bankers of Minnesota |
| ICBM | International Conference on Business and Management |
| ICC | International Criminal Court |
| ICC | International Cricket Council |
| ICC | International Code Council |
| ICC | International Conference on Communications |
| ICC | International Chamber of Commerce |
| ICC | International Commerce Centre |
| ICC | Internet Chess Club |
| ICC | Immaculate Conception College |
| ICC | Ifield Community College |
| ICCR | Indian Council for Cultural Relations |
| ICCR | Interfaith Center on Corporate Responsibility |
| ICCR | Interdisciplinary Centre for Comparative Research |
| ICCU | Intensive Coronary Care Unit |
| ICD | International Classification of Diseases |
| ICD | Implantable Cardioverter Defibrillator |
| ICD | In Circuit Debugger |
| ICD | Indian Creek Designs |
| ICD | Inland Container Depot |
| ICD | Investment Corporation of Dubai |
| ICDS | Integrated Child Development Services |
| ICDS | Integrated Cockpit Display Systems |
| ICDS | Ibn Khaldoun Center for Development Studies |
| ICE | Information and Content Exchange |
| ICE | Internal Combustion Engine |
| ICE | In-Circuit Emulation |
| ICE | Immigration and Customs Enforcement |
| ICE | Iron Crown Enterprises |
| ICERT | Indian Computer Emergency Response Team |
| ICERT | International Conference on Environmental Research and Technology |
| ICESCR | International Covenant on Economic, Social and Cultural Rights |
| ICEX | Ice Exercise |
| ICEX | Indian Commodity Exchange Limited |
| ICEX | Instituto Español del Comercio Exterior |
| ICF | International Coach Federation |
| ICF | Integral Coach Factory |
| ICF | Internet Connection Firewall |
| ICF | Inertial Confinement Fusion |
| ICF | Inter City Firm |
| ICF | Intracellular Fluid |
| ICF | International Cablemakers Federation |
| ICF | Itochu Chemical Frontier |
| ICF | Indian Christian Front |
| ICFAI | Institute of Chartered Financial Analysts of India |
| ICI | Iodine monochloride |
| ICICI | Industrial Credit and Investment Corporation of India |
| ICIMOD | International Centre for Integrated Mountain Development |
| ICJ | International Court of Justice |
| ICJ | International Commission of Jurists |
| ICL | Indian Cricket League |
| ICL | Imperial College London |
| ICL | Inrush Current Limiter |
| ICL | Idea Cellular Limited |
| ICL | International Computers Limited |
| ICMP | Internet Control Message Protocol |
| ICMP | International Confederation of Music Publishers |
| ICMP | International Congress on Mathematical Physics |
| ICMP | Ischemic Cardiomyopathy |
| ICMR | Indian Council of Medical Research |
| ICMR | International Center for Materials Research |
| ICMR | Irish Centre for Manufacturing Research |
| ico | Icon |
| ICO | Initial Coin Offering |
| ico | Information Commissioner’s Office |
| ICO | International Coffee Organization |
| ICO | Intermediate Circular Orbit |
| ICO | Institut Català d'Ornitologia |
| ICO | International Commission for Optics |
| ICO | International Council of Ophthalmology |
| ICO | Indian Computing Olympiad |
| ICO | Institute of Contemporary Observation |
| ICO | Illinois College of Optometry |
| ICO | Irish Chamber Orchestra |
| ICO | Israel Chamber Orchestra |
| ICO | Index of Central Obesity |
| ICO | Irish College of Ophthalmologists |
| ICRA | Internet Content Rating Association |
| ICRA | IEEE International Conference on Robotics and Automation |
| ICRA | Investment Information & Credit Rating Agency |
| ICRA | Immigration Reform and Control Act |
| ICRA | International Cultivation Registration Authority |
| ICRA | Indian Civil Rights Act |
| ICRA | Irish Civil Rights Association |
| ICRC | International Committee of the Red Cross |
| ICRC | International Cosmic Ray Conference |
| ICRC | International Clinical Research Center |
| ICRC | Infrastructure Concession Regulatory Commission |
| ICRC | International Conference of Reformed Churches |
| ICRC | Iran Color Research Center |
| ICRISAT | International Crops Research Institute for the Semi-Arid Tropics |
| ICS | Internet Connection Sharing |
| ICS | International Classification for Standards |
| ICS | Inventory Control System |
| ICS | Incident Command System |
| ICS | Indian Creek School |
| ICS | Integrated Computer Solutions |
| ICS | Intelligence and Security Committee |
| ICSE | International Conference on Software Engineering |
| ICSE | Indian Certificate of Secondary Education |
| ICSE | IEEE International Conference on Semiconductor Electronics |
| ICSE | International Contract Services Expo |
| ICSSR | Indian Council of Social Science Research |
| ICT | Information and Communication Technology |
| ICT | In-Circuit Test |
| ICT | Institute for Counter-Terrorism |
| ICT | International Campaign for Tibet |
| ICTACT | ICT Academy of Tamil Nadu |
| ICTV | International Committee on Taxonomy of Viruses |
| ICTV | Indigenous Community TeleVision |
| ICTV | Ithaca College TeleVision |
| ICTV | International Commercial TeleVision |
| ICU | Intensive Care Unit |
| ICU | International Components for Unicode |
| ICU | Imperial College Union |
| ICU | Inner City Unit |
| ICU | International Cheer Union |
| ICU | International Christian University |
| ICU | I See You |
| ICU | International Chalu Union |
| ICU | Investment Capital Ukraine |
| ICU | Istanbul Commerce University |
| ICU | Intersection Capacity Utilization |
| ICU | Information and Communications University |
| ICU | Islamic Courts Union |
| ICW | Intracoastal Waterway |
| ICW | Insane Championship Wrestling |
| ICW | International Council of Women |
| ICW | Internet Call Waiting |
| ICW | Interactive Courseware |
| ICW | Italian Championship Wrestling |
| ICWA | Indian Council of World Affairs |
| ICWA | Indian Child Welfare Act |
| ICWA | Insurance Commission Of Western Australia |
| ICWA | International Coil Winding Association |
| ICWAI | Institute of Cost and Works Accountants of India |
| ICYDK | In Case You Didn't Know |
| ICYMI | In Case You Missed It |
| ID | IDentification |
| ID | Indonesia |
| ID | Identifier |
| ID | Identity Document |
| ID | Infectious Disease(s) |
| ID | Independent Democrats |
| id | Indonesia (TLD) |
| IDB | Inter-American Development Bank |
| IDB | Islamic Development Bank |
| IDB | Internal Drainage Board |
| IDB | Industrial Development Bureau |
| IDB | Israel Discount Bank |
| IDB | Intel Debugger |
| IDB | IndexedDB |
| IDB | Irish Dairy Board |
| IDB | Industrial Development Bank |
| IDBI | Industrial Development Bank of India |
| IDC | International Data Corporation |
| IDC | Internet Data Center |
| IDC | I Don’t Care |
| IDC | Interdisciplinary Center |
| IDC | Insulation-Displacement Connector |
| IDC | Iris Deactivation Code |
| IDC | Ila Da Chilonzuene Airport |
| IDD | International Direct Dialling |
| IDE | Integrated Development Environment |
| IDE | Integrated Drive Electronics |
| iDE | International Development Enterprises |
| IDE | Insulin Degrading Enzyme |
| IDE | Investigational Device Exemption |
| IDE | Institute of Developing Economies |
| IDE | Instituto de Desenvolvimento Educacional |
| IDE | Investissements Directs à l’Étranger |
| IDE | Investimenti Diretti Esteri |
| IDE | Institut für Dokumentologie und Editorik |
| IDEA | Individuals with Disabilities Education Act |
| IDEA | International Debate Education Association |
| IDeA | Improvement and DEvelopment Agency |
| IDEA | International Data Encryption Algorithm |
| IDEA | International Institute for Democracy and Electoral Assistance |
| IDEO | combining form of the word “idea,” as in ‘ideology’ or ‘ideogram’ |
| IDEO | Intrepid Dynamic Exoskeletal Orthosis |
| IDEO | Institut dominicain d'études orientales |
| IDFC | Infrastructure Development Finance Company |
| IDK | I Don’t Know |
| IDRA | Intercultural Development Research Association |
| IDRA | Idera Pharmaceuticals |
| IDRA | Intermediate Data Recovery and Analysis |
| IDRBT | Institute for Development & Research in Banking Technology |
| IDRC | International Development Research Centre |
| IDRC | I Don’t Really Care |
| IDRC | Import Drag Racing Circuit |
| IDS | Intrusion Detection System |
| IDS | Istarski Demokratski Sabor |
| IDS | Integrated Defence Staff |
| IDS | Boeing Integrated Defense Systems |
| IDS | Institute of Development Studies |
| IDS | Iain Duncan Smith |
| IDS | Informix Dynamic Server |
| IDTIMWYTIM | I Don’t Think It Means What You Think It Means |
| IDV | Integrated Domestic Violence |
| IDV | Integrated Data Viewer |
| IDV | Independiente del Valle |
| IDV | Italia dei Valori |
| IDV | Insured Declared Value |
| ie | id est |
| IE | Internet Explorer |
| IE | Inland Empire |
| IE | Infective Endocarditis |
| IE | Solomon Airlines |
| IE | Ionization Energy |
| ie | Ireland (TLD) |
| IEA | International Energy Agency |
| IEC | International Electrotechnical Commission |
| IEC | Import Export Code |
| IEC | Israel Electric Corporation |
| IEC | Independent Electrical Contractors |
| IECC | International Energy Conservation Code |
| IECC | Integrated Electronic Control Centre |
| IECC | Illinois Eastern Community Colleges |
| IECC | Intercultural E-Mail Classroom Connections |
| IECC | Informix Enterprise Command Center |
| IED | Improvised Explosive Device |
| IED | Intelligent Electronic Device |
| IED | Institution of Engineering Designers |
| IED | Intermittent Explosive Disorder |
| IED | Institute for Economic Democracy |
| IEE | Idiopathic Eosinophilic Esophagitis |
| IEE | Independent Educational Evaluation |
| IEE | International Elevator & Equipment |
| IEE | Institution of Electrical Engineers |
| IEEE | Institute of Electrical and Electronics Engineers |
| IEEMA | Indian Electrical & Electronics Manufacturers’ Association |
| IEFT | International Education Fairs of Turkey |
| IEFT | Indigenous Education Foundation of Tanzania |
| IEIA | International Electricity Infrastructure Assurance |
| IEIA | Indian Exhibition Industry Association |
| IELTS | International English Language Testing System |
| IEM | In Ear Monitor |
| IEM | Inborn Errors of Metabolism |
| IEM | Innovative Emergency Management |
| IEM | Industrial Engineering and Managemen |
| IEM | Internal Electricity Market |
| IEM | Institute of Engineering & Management |
| IES | Institute of Education Sciences |
| IES | Indian Engineering Services |
| IES | Industrial Electronics Society |
| IES | Institution of Engineers Singapore |
| IES | Ideal Educational Society |
| IETE | Institution Of Electronics and Telecommunication Engineers |
| IETF | Internet Engineering Task Force |
| IETF | International Engineering and Technology Fair |
| IFAD | International Fund for Agricultural Development |
| IFB | Invitation For Bid |
| IFB | Indian Fine Blanks |
| IFBB | International Federation of BodyBuilding and Fitness |
| IFBB | Independent Family Brewers of Britain |
| IFBB | Institute for Food, Brain and Behaviour |
| IFBI | Institute of Finance, Banking and Insurance |
| IFC | International Finance Corporation |
| IFC | Independent Film Channel |
| IFCA | Independent Fundamental Churches of America |
| IFCA | International Financial Cryptography Association |
| IFCI | Industrial Finance Corporation of India |
| IFFCO | Indian Farmers Fertiliser Cooperative |
| IFFK | International Film Festival of Kerala |
| IFOAM | International Federation of Organic Agriculture Movements |
| IFRS | International Financial Reporting Standards |
| IFS | International Food Standard |
| IFS | Indian Forest Service |
| IFS | Indian Foreign Service |
| IFS | Installable File System |
| IFS | Independent Front Suspension |
| IFSC | International Financial Services Centre |
| IFSC | Indian Financial System Code |
| IFSC | International Federation of Sport Climbing |
| IFTTT | If This Then That |
| IG | Instagram |
| Ig | Immunoglobulin |
| IG | Inspector General |
| IG | Air Italy |
| IG | Italian Greyhound |
| IG | Insulated Glazing |
| iG | Internet Group |
| IG | Irish Guards |
| IG | Imperial Gallon |
| IG | Integrated Graphics |
| IGBT | Insulated Gate Bipolar Transistor |
| IGCAR | Indira Gandhi Centre for Atomic Research |
| IGCSE | International General Certificate of Secondary Education |
| IGHC | IATA Ground Handling Council |
| IGHC | Institute on Globalization and the Human Condition |
| IGI | International Genealogical Index |
| IGMDP | Integrated Guided Missile Development Program |
| IGMSY | इंदिरा गांधी मातृत्व सहयोग योजना |
| IGN | Imagine Games Network |
| IGN | Instituto Geográfico Nacional |
| IGN | Instituto Geográfico Nacional |
| IGN | Institut Géographique National |
| IGN | Institut Géographique National |
| IGN | Iodine Global Network |
| IGN | Maria Cristina Airport |
| IGNOU | Indira Gandhi National Open University |
| IGO | Inter-Governmental Organization |
| IGO | Chigorodo Airport |
| IGP | Integrated Graphics Processor |
| IGP | Interior Gateway Protocol |
| IGRP | Interior Gateway Routing Protocol |
| IGS | International GNSS Service |
| IGS | Interactive Geometry Software |
| IGS | International Grammar School |
| IGS | Indian Geotechnical Society |
| IGS | IBM Global Services |
| IGS | Internet Go Server |
| IGS | Intergenic Spacer |
| IGS | Indian Government Service |
| IGS | Image-Guided Surgery |
| IGS | Information Gateway Services |
| IGS | Information Global Service |
| IGS | International Games System |
| IGS | Information Gathering Satellite |
| IGS | Institute of General Semantics |
| IGS | International Glaciological Society |
| IGS | Ilkley Grammar School |
| IGS | Ipswich Grammar School |
| IGS | Ivanhoe Grammar School |
| IGS | Imerslund-Gräsbeck Syndrome |
| IGS | Irish Georgian Society |
| IGS | Institute of Governmental Studies |
| IGS | Ingolstadt Manching Airport |
| IGS | Islington Green School |
| IGS | International Graduates Scheme |
| IGST | Integrated Goods and Services Tax |
| IGST | International Golf Society of Taipei |
| IGSTPP | Indira Gandhi Super Thermal Power Project |
| IGTM | International Golf Travel Market |
| IGTM | Indie Game: The Movie |
| IGTV | Instagram TV |
| IHFF | International Health, Sports and Fitness Festival |
| IHRD | International Human Rights Day |
| IHRD | Institute of Human Resources Development |
| IIAEM | International Institute for Aerospace Engineering and Management |
| IIAS | Inventory Information Approval System |
| IIAS | Indian Institute of Advanced Study |
| IIAS | International Institute of Administrative Sciences |
| IIAS | International Institute for Asian Studies |
| IIAS | International Internet Advertising Services |
| IIBF | Indian Institute of Banking & Finance |
| IICA | Indian Institute of Corporate Affairs |
| IICA | Inter-American Institute for Cooperation on Agriculture |
| IIE | Institute of International Education |
| IIE | Institute of Industrial Engineers |
| IIE | Institution of Incorporated Engineers |
| IIFA | International Indian Film Academy |
| IIFA | Irish International Freight Association |
| IIIT | Indian Institutes of Information Technology |
| IIM | Indian Institutes of Management |
| IIM | Institute of Interim Management |
| IIM | Indian Institute of Metals |
| IIM | IC Identification Module |
| IIN | Issuer Identification Number |
| IIN | Idea Internet Network |
| IIN | Intelligent Information Network |
| IIN | Institute for Integrative Nutrition |
| IIN | Is It Normal |
| IIN | IiNet Limited |
| IIN | Instituto de Investigación Nutricional |
| IIN | Indigenous Information Network |
| IIN | Interferometric Intensity Noise |
| IIN | Institute for Nanotechnology |
| IIN | Instituto Indigenista Nacional |
| IIPM | Indian Institute of Planning and Management |
| IIPM | Indian Institute of Pharmaceutical Marketing |
| IIPM | IndianOil Institute of Petroleum Management |
| IIPM | International Institute of Psychosomatic Medicine |
| IIS | Internet Information Services |
| IIS | Indian Information Service |
| IIS | Institute of Ismaili Studies |
| IIS | Nissan Island Airport |
| IIS | Iraqi Intelligence Service |
| IISc | Indian Institute Of Science |
| IISER | Indian Institutes of Science Education and Research |
| IISER | Integrated Information System on European Researchers |
| IISH | International Institute of Social History |
| IISH | Indian Institute of Scientific Heritage |
| IIT | Indian Institute of Technology |
| IIT | Illinois Institute of Technology |
| IIT | Italian Institute of Technology |
| IIT | Impulse Invariant Transform |
| IIT-JEE | Indian Institute of Technology Joint Entrance Examination |
| IITB | Indian Institute of Technology Bombay |
| IITM | Indian Institute of Technology Madras |
| IITM | Indian Institute of Tropical Meteorology |
| IITRI | IIT Research Institute |
| IJELLH | International Journal of English Language, Literature and Humanities |
| IJESRT | International Journal of Engineering Sciences & Research Technology |
| IJF | International Judo Federation |
| IJF | Internacia Junulara Festivalo |
| IJS | I’m Just Saying |
| IJS | Institut Jožef Stefan |
| IJS | International Journal of Security |
| IJSO | International Junior Science Olympiad |
| IKDRC | Institute of Kidney Diseases and Research Centre |
| IKEA | Ingvar Kamprad Elmtaryd Agunnaryd |
| IKIU | Imam Khomeini International University |
| IKR | I Know, Right |
| ikr | Króna |
| IKR | Iklehra Railway Station |
| IL&FS | Infrastructure Leasing & Financial Services |
| ILD | Interstitial Lung Disease |
| ILD | Institute for Liberty and Democracy |
| ILD | Injection Laser Diode |
| ILD | Indentation Load-Deflection |
| ILD | Lleida–Alguaire Airport |
| ILD | International Labor Defense |
| ILD | International Liaison Department |
| ILD | Internet Listing Display |
| ILO | International Labour Organization |
| iLO | Integrated Lights-Out |
| ilo | Ilocano |
| ILO | Iloilo International Airport |
| ILO | Initial License Offering |
| ILO | International Left Opposition |
| ILO | Injection-Locked Oscillator |
| ILS | International Launch Services |
| ILS | Internet Locator Server |
| ILS | Integrated Library System |
| ILS | Integrated Learning Systems |
| ILS | Instrument Landing System |
| ILU | I Love You |
| ILU | Kilaguni Airport |
| ILU | Inter-Language Unification |
| ILU | Iluka Resources Limited |
| ILY | I Love You |
| ILY | Islay Airport |
| IM | Instant Messaging |
| IM | Isle of Man |
| IM | Injection Molding |
| IM | Intake Manifold |
| IM | Intensity Modulation |
| IM | Ingram Micro |
| IM | Induction Motor |
| IM | Infectious Mononucleosis |
| IM | Indian Mujahideen |
| im | Isle of Man (TLD) |
| IM | Index Medicus |
| IM | Imatinib Mesylate |
| IMA | Institute of Management Accountants |
| IMA | Indian Medical Association |
| IMA | Indian Military Academy |
| IMA | Integrated Motor Assist |
| IMA | Inferior Mesenteric Artery |
| IMA | Internal Mammary Artery |
| IMA | Institut du Monde Arabe |
| IMA | International Mineralogical Association |
| IMA | Israel Medical Association |
| IMA | Integrated Modular Avionics |
| IMA | Illinois Manufacturers’ Association |
| IMA | Industria Macchine Automatiche |
| IMA | Institute for Mathematics and its Applications |
| IMA | Institute of Mathematics and Applications |
| IMA | Indianapolis Museum of Art |
| IMA | Institute of Mathematics and its Applications |
| IMA | International Mycological Association |
| IMA | Investment Management Association |
| IMA | Inverse Multiplexing for ATM |
| IMA | Ideomotor Apraxia |
| IMA | International Marinelife Alliance |
| IMA | Irish Museums Association |
| IMA | Instituto Miguel Ángel |
| IMA | Interactive Multimedia Association |
| IMA | Illinois Mycological Association |
| IMA | iSCSI Management API |
| iMAC | Internet Macintosh |
| IMAC | International Miniature Aerobatic Club |
| IMAGE | Imager for Magnetopause-to-Aurora Global Exploration |
| IMAGE | Intervention with Microfinance for AIDS and Gender Equity |
| IMAGE | Illinois Measure of Annual Growth in English |
| IMAGE | Integrated Model to Assess the Greenhouse Effect |
| IMAGE | Indian Medical Association Goes Eco-friendly |
| IMAJS | Image + JavaScript |
| IMAO | In My Arrogant Opinion |
| IMAP | Internet Message Access Protocol |
| IMAP | Integrating Mathematics and Pedagogy |
| IMARK | Information Management Resource Kit |
| IMAX | Image MAXimum |
| IMDb | Internet Movie Database |
| IMEI | International Mobile Equipment Identity |
| IMF | International Monetary Fund |
| IMF | International Myeloma Foundation |
| IMF | Imphal Airport |
| IMFL | Indian Made Foreign Liquor |
| IMG | Image |
| IMG | Image file |
| IMG | International Management Group |
| IMG | International Medical Graduate |
| IMG | International Medical Group |
| IMG | Inside Mac Games |
| IMG | International Medical Group |
| IMG | Interferometric Monitor for Greenhouse Gases |
| IMG | Idiopathic Membranous Glomerulonephritis |
| IMG | Isuzu Motors Germany |
| IMG | Iamgold Corporation |
| IMG | Integrated Microbial Genomes |
| IMG | In-Mould-Graining |
| IMG | Inhaminga Airport |
| IMG | International Marxist Group |
| IMHO | In My Humble Opinion |
| IMO | International Maritime Organization |
| IMO | In My Opinion |
| IMO | Irish Medical Organisation |
| iMO | Instant Money Order |
| IMO | International Mathematics Olympiad |
| IMO | Zemio Airport |
| Imp | Important |
| IMP | Internet Messaging Program |
| IMP | International Masters Publishers |
| IMP | Interface Message Processor |
| IMPS | Immediate Payment Service |
| IMPS | Integrated Microcomputer Processing System |
| IMPS | Internet Miniature Pinscher Service |
| IMPS | Instant Messaging and Presence Service |
| IMS | Information Management System |
| IMS | Institute of Mechatronic Systems |
| IMS | IP Multimedia Subsystem |
| IMS | Institute of Mathematical Statistics |
| IMS | Indian Missionary Society |
| IMS | Industrial Methylated Spirits |
| IMS | Madison Municipal Airport |
| IMS | Ingomar Middle School |
| IMSI | International Mobile Subscriber Identity |
| IMSI | International Maple Syrup Institute |
| IMSI | Idaho Maximum Security Institution |
| IMSI | Intracytoplasmic Morphologically-selected Sperm Injection |
| IMTMA | Indian Machine Tool Manufacturers¹ Association |
| IN | India |
| IN | Indiana |
| In | Input |
| In | Indium |
| in | India (TLD) |
| INA | Indonesia |
| INA | Institute of Nautical Archaeology |
| INA | Indian Naval Academy |
| INA | Institut national de l’audiovisuel |
| INA | Iraqi National Accord |
| INA | Insurance Company of North America |
| INA | l’Institut National des Arts |
| INA | Indian National Airways |
| INA | Istituto Nazionale delle Assicurazioni |
| INA | Indian National Army |
| INA | Inta Airport |
| INA | Iowa Nurses Association |
| iNA | intrinsic Noise Analyzer |
| Inc | Incorporated |
| INC | Indian National Congress |
| INC | Yinchuan Hedong International Airport |
| INCOIS | Indian National Center for Ocean Information Services |
| INCOSPAR | Indian National Committee for Space Research |
| IND | India |
| IND | Investigational New Drug |
| Ind | Industries/Industry/Industrial |
| IND | Immigration and Nationality Directorate |
| IND | Improvised Nuclear Devices |
| Ind AS | Indian Accounting Standard |
| India | the name India is derived from the “Indus” river |
| Indy 500 | Indianapolis 500 |
| IndyCar | derived as a result of its link to the Indianapolis 500 (Indy 500) |
| INFAM | Indian Farmer’s Movement |
| Info | Information |
| INFO | Inside Nepal Friendship Organization |
| INFO | Information Network For Ontario |
| Infosys | Information Systems |
| Infotech | Information + Technology |
| Ing | Ingenieur |
| ING | Isaac Newton Group |
| ING | Lago Argentino Airport |
| ING | Iraqi National Guard |
| INGO | International Non-Governmental Organization |
| INR | India Rupee |
| INR | Institute of National Remembrance |
| INR | International Normalized Ratio |
| INRI | Iesus Nazarenus, Rex Iudaeorum |
| INS | Inertial Navigation System |
| INS | Immigration and Naturalization Service |
| INSAS | Indian Small Arms System |
| INSAT | Indian National Satellite System |
| INSEAD | Institut Européen d’Administration des Affaires |
| Inst | Institute |
| Inst | Instrument/Instrumental |
| Inst | Install/Installation |
| Inst | Instant/instante mense |
| Insta | Instagram |
| INTACH | Indian National Trust For Art and Cultural Heritage |
| INTAM | Indian National Television Audience Measurement |
| Intel | Integrated Electronics |
| Intel | Intelligence |
| INTERCOM | Intercommunication |
| Internet | Internetwork |
| INTERPOL | International Criminal Police Organization |
| INTUC | Indian National Trade Union Congress |
| IOA | Indian Olympic Association |
| IOB | Indian Overseas Bank |
| IOB | Intelligence Oversight Board |
| IoB | Institute of Biology |
| IOB | Iranian Oil Bourse |
| IOC | International Olympic Committee |
| IOC | Indian Oil Corporation |
| IOC | Immediate Or Cancel |
| IOC | International Olive Council |
| IOC | Initial Operating Capability |
| IOC | Iron Ore Company of Canada |
| IOC | Indicator Of Compromise |
| IOC | IntraOral Camera |
| IOC | Integrated Optical Circuit |
| IOC | Indian Orthodox Church |
| IOC | International Order of Characters |
| IoC | Inversion of Control |
| IOCL | Indian Oil Corporation Limited |
| IOPS | Input/Output Operations Per Second |
| iOS | iPhone Operating System |
| IOS | Internetwork Operating System |
| IOS | Input/Output Supervisor |
| IOS | Ilheus/Bahia-Jorge Amado Airport |
| IOS | Institute of Ocean Sciences |
| IOS | International Online Soccer |
| IOSH | Institution of Occupational Safety and Health |
| IoT | Internet of Things |
| IOT | Inductive Output Tube |
| IOT | Illuminates of Thanateros |
| IOT | Indian Chagos Time |
| IOT | Illorsuit Heliport |
| IOTP | Internet Open Trading Protocol |
| IOU | I Owe You |
| IOU | Indian Ocean University |
| IOU | Islamic Online University |
| IOU | Investor-Owned Utility |
| IP | Internet Protocol |
| IP | Intellectual Property |
| IP | Inpatient |
| IP | International Paper Company |
| IP | Ipswich |
| IP | Iraqi Police |
| IP | International non-Proprietary name |
| IP | Incontinentia Pigmenti |
| IP67 | International Protection 67 |
| IPA | IsoPropyl Alcohol |
| IPA | India Pale Ale |
| IPA | International Phonetic Alphabet |
| IPA | International Police Association |
| IPA | International Psychoanalytical Association |
| IPA | Instrument for Pre-Accession Assistance |
| IPA | International Publishers Association |
| IPA | International Phonetic Association |
| IPA | Insolvency Practitioners Association |
| IPA | International Permafrost Association |
| IPA | International Play Association |
| IPA | International Polka Association |
| IPA | Institute of Public Accountants |
| IPA | Institute of Public Affairs |
| IPA | Indian Polo Association |
| IPA | Indian Pharmacist Association |
| IPC | Instructions Per Cycle |
| IPC | International Patent Classification |
| IPC | Inter-Process Communication |
| IPC | Indian Penal Code |
| IPC | International Paralympic Committee |
| IPC | Information and Privacy Commissioner |
| IPC | Iraq Petroleum Company |
| IPCC | Intergovernmental Panel on Climate Change |
| IPCC | Independent Police Complaints Commission |
| IPCC | Integrated Professional Competence Course |
| IPCC | International Pentecostal Church of Christ |
| IPCC | Irish Peatland Conservation Council |
| IPCP | Internet Protocol Control Protocol |
| IPD | Interactive Pager Backup |
| IPEC | International Programme on the Elimination of Child Labour |
| IPEC | International Pharmaceutical Excipients Council |
| IPGCL | Indraprastha Power Generating Company Limited |
| IPHA | Indian Public Health Association |
| IPL | Indian Premier League |
| IPL | Intense Pulsed Light |
| IPL | Indonesian Premier League |
| IPL | Iran Pro League |
| IPL | Instituto Politécnico de Leiria |
| IPL | Instituto Politécnico de Lisboa |
| IPL | Instituto Politécnico Loyola |
| IPL | India Pale Lager |
| IPL | Inferior Parietal Lobule |
| IPL | Imperial County Airport |
| IPL | Initial Program Load |
| IPL | Interrupt Priority Level |
| IPL | Indianapolis Power & Light |
| IPL | Interstate Power and Light |
| IPL | Infiniti Performance Line |
| IPL | Internet Public Library |
| IPL | Information Processing Language |
| IPL | Israeli Premier League |
| IPL | Interoperable PDK Libraries |
| IPL | IBM Public License |
| IPMI | Intelligent Platform Management Interface |
| IPMI | International Precious Metals Institute |
| IPO | Initial Public Offering |
| IPO | Intellectual Property Office |
| IPO | Interdecadal Pacific Oscillation |
| IPO | Interprocedural Optimization |
| IPO | Indian Patent Office |
| IPO | Israel Philharmonic Orchestra |
| IPO | Instituto Português de Oncologia |
| IPO | Intellectual Property Owners |
| IPR | Intellectual Property Rights |
| IPS | Indian Police Service |
| IPS | In-Plane Switching |
| IPS | Inter Press Service |
| ips | Inch per second |
| IPS | Indianapolis Public Schools |
| IPS | Instructions Per Second |
| IPS | Ice Protection Systems |
| IPS | Intrusion Prevention System |
| IPS | Identity and Passport Service |
| IPS | Institute for Palestine Studies |
| IPS | Indian Psychiatric Society |
| IPSec | Internet Protocol Security |
| IPSEC | Indian Point Safe Energy Coalition |
| IPTL | Independent Power Tanzania Limited |
| IPTL | International Premier Tennis League |
| IPTL | Instituto Professional de Transportes e Logistica |
| IPTL | Isobaric Peptide Termini Labeling |
| IPTV | Internet Protocol Television |
| IPTV | Iowa Public Television |
| IPV4 | Internet Protocol version 4 |
| IPV6 | Internet Protocol version 6 |
| IPX/SPX | Internetwork Packet Exchange/Sequenced Packet Exchange |
| IQ | Intelligence Quotient |
| IQ | Iraq |
| iq | Iraq (TLD) |
| IQ | Image Quality |
| IQ | Installation Qualification |
| IQ | Information Quality |
| IQ | Intelligent Qube |
| IQ | Industries Qatar |
| IQ | Institute of Quarrying |
| IQ | Qazaq Air |
| IQ | Inuit Qaujimajatuqangit |
| iq | idem quod |
| IR | Infrared |
| IRA | Individual Retirement Arrangement |
| IRA | Irish Republican Army |
| IRA | International Reading Association |
| IRA | Islamabad Rugby Association |
| IRBM | Intermediate-Range Ballistic Missile |
| IRBM | Integrated River Basin Management |
| IRC | Internet Relay Chat |
| IRCON | Indian Railway Construction Company Limited |
| IRCTC | Indian Railway Catering and Tourism Corporation |
| IrDA | Infrared Data Association |
| IRDA | Indian Runner Duck Association |
| IRDA | Insurance Regulatory and Development Authority |
| IRDA | Iskandar Regional Development Authority |
| IRDAI | Insurance Regulatory and Development Authority of India |
| IRDE | Instruments Research & Development Establishment |
| IRDP | Integrated Rural Development Programme |
| IRDP | ICMP Router Discovery Protocol |
| IRF | International Road Federation |
| IRF | International Rhino Foundation |
| IRF | Islamic Research Foundation |
| IRF | Initial Reaction Force |
| IRF | Institute of Retirement Funds |
| IRF | Intrasis Raw File |
| IRFCA | Indian Railways Fan Club |
| IRIS | Integrated Risk Information System |
| IRIS | Incorporated Research Institutions for Seismology |
| IRIS | International Research Institute of Stavanger |
| IRIS | Insurance Regulatory Information Systems |
| IRIS | Immune Reconstitution Inflammatory Syndrome |
| IRIS | Internal Rotary Inspection System |
| IRL | Ireland |
| IRL | In Real Life |
| IRL | Indy Racing League |
| IRL | Indian River Lagoon |
| IRL | Industrial Research Limited |
| IRNSS | Indian Regional Navigation Satellite System |
| IROAF | Indian Railways Organization for Alternate Fuels |
| IRPSM | Indian Railways Projects Sanctions Management |
| IRQ | Interrupt request |
| IRS | Internal Revenue Service |
| IRS | Indian Revenue Service |
| IRS | Interest Rate Swap |
| IRS | Investor Relations Society |
| IRS | Insulin Receptor Substrate |
| IRS | Indian Remote Sensing |
| IRS | Indian Register of Shipping |
| IRS | Institute of Regional Studies |
| IRS | Independent Rear Suspension |
| IRS | Kirsch Municipal Airport |
| IRVM | Inside Rear View Mirror |
| IRVM | Integrated Roadside Vegetation Management |
| IS | Iceland |
| IS | Insertion Sequence |
| IS | Information System |
| IS | Image stabilization |
| IS | Information Services |
| IS | Ilta-Sanomat |
| is | Iceland (TLD) |
| IS | Iaşi County |
| IS | Incentive Spirometer |
| IS-IS | Intermediate System to Intermediate System |
| ISA | Industry Standard Architecture |
| ISA | Internet Security and Acceleration |
| ISAC | ISRO Satellite Centre |
| ISAC | Iowa State Association of Counties |
| ISAC | Information Sharing and Analysis Center |
| ISAC | International Society for Advancement of Cytometry |
| ISAC | Idol Star Athletics Championships |
| ISAC | Istituto di Scienze dell'Atmosfera e del Clima |
| ISAC | Institute for the Study of American Cultures |
| ISACA | Information Systems Audit and Control Association |
| ISAM | Indexed Sequential Access Method |
| ISAM | International Society for Aerosols in Medicine |
| ISB | Indian School of Business |
| ISB | Institute for Systems Biology |
| ISBN | International Standard Book Number |
| ISBT | International Society of Blood Transfusion |
| ISBT | Inter State Bus Terminals |
| ISBT | International Society of Beverage Technologists |
| ISC | Internet Systems Consortium |
| ISC | Internet Storm Center |
| ISC | International Speedway Corporation |
| ISC | Indian School Certificate |
| Isc | Short-Circuit Current |
| ISC | International Sculpture Center |
| ISC | Idle Speed Control |
| ISC | Inter-State Council |
| ISC | India Study Channel |
| ISC | St Mary’s Airport |
| ISC | International Sports Clothing |
| ISC | International Songwriting Competition |
| ISC | IP Solution Center |
| ISC | Imperial Sugar Company |
| ISC | International Seismological Centre |
| ISC | Internet Society of China |
| ISC | Internet Scrabble Club |
| ISC | International School of Choueifat |
| ISC | Indian subcontinent |
| ISC | Independent Schools Council |
| ISC | Irish Sports Council |
| ISC | Itchenor Sailing Club |
| ISC | Indira School of Communication |
| ISC | Indian Solidarity Council |
| ISCII | Indian Standard Code for Information Interchange |
| iSCSI | Internet Small Computer System Interface |
| ISD | International Subscriber Dialing |
| ISDN | Integrated Services Digital Network |
| ISES | International Solar Energy Society |
| ISES | International Special Events Society |
| ISES | International Society for Equitation Science |
| ISES | International Student Energy Summit |
| ISES | International Space Environment Service |
| ISES | International Society of Endovascular Specialists |
| ISI | Inter-Services Intelligence |
| ISI | Indian Statistical Institute |
| ISI | Indian Standards Institution |
| ISI | Information Sciences Institute |
| ISI | International Statistical Institute |
| ISIC | International Standard Industrial Classification |
| ISIC | International Student Identity Card |
| Isis | Egyptian goddess of fertility and motherhood |
| ISIS | Islamic State of Iraq and Syria |
| ISIS | International Species Information System |
| ISIS | Institute for Software Integrated Systems |
| ISIS | Imaging Science and Information Systems |
| ISIS | Institute for Surface and Interface Science |
| ISIS | Intermediate System to Intermediate System |
| ISIS | Institute for the Secularisation of Islamic Society |
| ISIS | International School of Information Science |
| ISIS | Integrated Software for Imagery and Spectrometers |
| ISKCON | International Society for Krishna Consciousness |
| ISL | Iceland |
| ISL | Indian Super League |
| isl | Icelandic |
| ISL | Independent School League |
| ISL | In-Situ Leaching |
| ISL | Institute of State and Law |
| isl | Integer set library |
| ISL | Inter-Switch Link |
| ISL | International School of Luxembourg |
| ISL | Isleworth Railway Station |
| ISL | International School of Louisiana |
| ISL | Institute of Shipping Economics and Logistics |
| ISL | International School of Lausanne |
| ISL | International School of Lusaka |
| ISL | Island Soccer League |
| ISL | Intercon Security Limited |
| ISM | Industrial, Scientific and Medical |
| ISM | Institute for Supply Management |
| ISM | International Safety Management |
| ISM | Indian School of Mines |
| ISM | Industrial Standard Malayalam |
| ISO | derived from the Greek isos, meaning “equal” |
| ISO | In Search Of |
| ISO | refers to the ISO norm for sensitivity of Photographic film or image sensors sensitivity to light |
| ISO | Insurance Services Office |
| ISO | Independent System Operator |
| ISO | Interstedelijk Studenten Overleg |
| ISO | Isolated Power |
| ISO | ISO image file format, from the ISO 9660 file system |
| ISO | Infrared Space Observatory |
| ISO | Imperial Service Order |
| ISO | Incentive Stock Option |
| ISO | Intermarket Sweep Order |
| ISO | Indianapolis Symphony Orchestra |
| ISO | Imamia Students Organization |
| ISO | Internal Security Organisation |
| ISO | International Socialist Organization |
| ISO | International Socialist Organisation |
| ISO | Internationale Sozialistische Organisatio |
| ISO | International Science Olympiad |
| ISO | Isorhapontigenin |
| ISO | Kinston Regional Jetport |
| ISO | Iceland Symphony Orchestra |
| ISO | International Socialist Organisation |
| ISO | International Symphony Orchestra |
| ISOC | Internet Society |
| ISOC | Internal Security Operations Command |
| ISP | Internet Service Provider |
| ISP | In-System Programming |
| ISP | Indiana State Police |
| ISP | Idaho State Police |
| ISP | International School of Paris |
| ISP | Illinois State Police |
| ISP | Long Island MacArthur Airport |
| ISRO | Indian Space Research Organisation |
| ISS | International Space Station |
| ISS | In-School Suspension |
| ISS | Internet Security Systems |
| ISS | Idea Star Singer |
| ISS | Instruction Set Simulator |
| ISS | Wiscasset Airport |
| ISS | Indian Springs School |
| ISS | Ion Scattering Spectroscopy |
| ISS | Infoseek Software Systems |
| ISSA | Information Systems Security Association |
| ISSA | International Social Security Association |
| ISSA | International Sports Sciences Association |
| ISSA | International Slurry Surfacing Association |
| ISSA | Indian Academy of Social Science |
| ISSN | International Standard Serial Number |
| ISSN | International Society of Sports Nutrition |
| ISSN | International Studies Schools Network |
| ISSN | International Society for the Study of Narrative |
| IST | Indian Standard Time |
| ISTQB | International Software Testing Qualifications Board |
| ISTRO | International Soil Tillage Research Organisation |
| IT | Information Technology |
| it | Italian |
| IT | Income Tax |
| IT | Gartner |
| IT | Immunotherapy |
| IT | Indian Thoughts |
| ITARDA | Institute for Traffic Accident Research and Data Analysis |
| ITBP | Indo-Tibetan Border Police |
| ITC | International Trade Commission |
| ITC | Institute of Technology of Cambodia |
| ITC | Investment Tax Credit |
| ITC | International Theological Commission |
| ITC | Imperial Tobacco Company |
| ITC | Institute of Texan Cultures |
| ITC | International Teledemocracy Centre |
| ITC | International Typeface Corporation |
| ITCTC | Ithaca-Tompkins County Transportation Council |
| ITCZ | Intertropical Convergence Zone |
| ITER | International Thermonuclear Experimental Reactor |
| ITER | International Toxicity Estimates for Risk |
| ITER | In-Training Evaluation Report |
| ITER | Institute of Technical Education and Research |
| ITES | Information Technology Enabled Services |
| ITES | International Teacher Exchange Services |
| ITES | International Test & Engineering Services |
| ITES | Institute for Tropical Ecosystem Studies |
| ITI | Industrial Training Institute |
| ITI | Information Technology Institute |
| ITI | International Theatre Institute |
| ITI | Indian Telephone Industries |
| ITI | Institute of Translation & Interpreting |
| ITI | International Trachoma Initiative |
| ITI | Intercultural Theatre Institute |
| ITI | Information Trust Institute |
| ITI | International Training Institute |
| ITI | International Theological Institute |
| ITI | Itambacuri Airport |
| ITI | Infrastructure Technology Institute |
| ITI | Integrated Thematic Instruction |
| ITO | Information Technology Outsourcing |
| ITO | Hilo International Airport |
| ITO | Indium Tin Oxide |
| ITO | Income Tax Officer |
| ITPL | Information Technology Park Limited |
| ITR | Income Tax Return |
| ITR | Integrated Test Range |
| ITR | Indiana Toll Road |
| ITR | Integra Type R |
| ITR | Itwari |
| ITR | Institute for Telecommunications Research |
| ITR-V | Income Tax Return–Verification |
| ITSA | Intelligent Transportation Society of America |
| Ittiam | I Think, Therefore I AM |
| ITU | International Telecommunication Union |
| ITU | Intensive Therapy Unit |
| ITU | International Technological University |
| ITU | Image Transfer Unit |
| ITU | Institute for Transuranium Elements |
| ITU | Istanbul Teknik Universitesi |
| ITU | Intent to Use |
| ITU | International Triathlon Union |
| ITX | Information Technology eXtended |
| ITX | Isopropylthioxanthone |
| ITX | Information Technology Experts |
| IUC | Interconnection Usage Charges |
| IUC | Inter-University Center for Japanese Language Studies |
| IUC | IntraUterine Contraceptive |
| IUC | International University College |
| IUC | International University of Chabahar |
| IUCN | International Union for Conservation of Nature and Natural Resources |
| IUFRO | International Union of Forest Research Organizations |
| IUI | Intrauterine Insemination |
| IUI | Intelligent User Interface |
| iUI | iPhone User Interface |
| IUML | Indian Union Muslim League |
| IUMS | Iran University of Medical Sciences |
| IUMS | International Union of Microbiological Societies |
| IUMS | International Union of Muslim Scholars |
| IUMS | Isfahan University of Medical Sciences |
| IUMS | International Union of Muslim Scouts |
| IUPAC | International Union of Pure and Applied Chemistry |
| IUT | International Union of Tenants |
| IUT | Isfahan University of Technology |
| IV | Intravenous |
| IV | Roman numeral for four (4) |
| IV | Implied Volatility |
| IV | Iodine Value |
| IV | Initialization Vector |
| IV | Instrumental Variables |
| IV | Inverness |
| IV | Intellectual Ventures |
| IV | Immigration Voice |
| IV | International Viewpoint |
| IV | Isla Vista |
| IV | Industrial Visit |
| IV | Irish Volunteers |
| IVAO | International Virtual Aviation Organisation |
| IVAO | Installation Voting Assistance Officer |
| IVF | In Vitro Fertilisation |
| IVF | Intervertebral Foramen |
| IVR | Interactive Voice Response |
| IVRCL | Iragavarapu Venkata Reddy Construction Limited |
| IVRS | Interactive Voice Response System |
| IVRS | Iowa Vocational Rehabilitation Services |
| iVTEC | Intelligent Variable Valve Timing and Lift Electronic Control |
| IWESS | Intelligent Workplace Energy Supply System |
| IYF | International Youth Foundation |
| IYF | International Youth Fellowship |
