| ICAAD | Interactive Computer-Aided Analysis and Design | In English | → Computer-based techniques |
| ICAAE | International Center for Aquaculture and Aquatic Environments | In English | → Organizations and associations → Fishing, hunting |
| ICAANE | International Congress on the Archaeology of the Ancient Near East | In English | → Congresses → Archeology |
| ICAD | International Conference on Alzheimer's Disease (and Related Disorders) | In English | → Congresses → Neurology |
| ICAD | International Conference on Auditory Display | In English | → Congresses → Human-computer interaction → Telecommunications |
| ICAE | Integrated Computer-Aided Engineering | In English | → Serial publications, periodicals → Computer-based techniques → Engineering, technology |
| ICAM | Intercellular Adhesion Molecule | In English | → Biochemistry, biophysics |
| ICAM | Integrated Computer-Aided Manufacturing | In English | → Computer-based techniques → Engineering, technology |
| ICAMES | Interuniversity Consortium for Arab and Middle Eastern Studies | In English | → Organizations and associations → Area studies |
| ICANAS | International Congress for Asian and Northern African Studies | In English | → Congresses → Area studies |
| ICANN | International Conference on Artificial Neural Networks | In English | → Congresses → Artificial intelligence |
| ICANN | Internet Corporation for Assigned Names and Numbers (www.icann.org) | In English | → Networks, communication |
| ICAO | International Civil Aviation Organization = IOCA | Internacia Organizo pri Civila Aviado | In Esperanto |
In English | → Organizations and associations → Aeronautics, aircraft → Transport and postal services |
| ICAOB | ICAO Bulletin (International Civil Aviation Organization) | In English | → Serial publications, periodicals → Aeronautics, aircraft → Transport and postal services |
| ICAP | International Conference on Atomic Physics | In English | → Congresses → 53198 |
| ICAP | Idaho Child Abuse Prevention (Coalition) (www.idahosheart.org) | In English | → Organizations and associations → Sexual problems → Law, jurisprudence |
| ICAPC | Increased-Capability Adaptive Payload Carrier | In English | |
| ICAR | Initiated Corrective Action Report | In English | |
| ICAR | Investigation and Corrective Action Report | In English | |
| ICAR | Indian Council of Agricultural Research | In English | → Agricultural sciences |
| ICARDA | International Center for Agricultural Research in the Dry Areas | In English | → Research institutes → Agricultural sciences |
| ICAROAP | International Co-operative Alliance Regional Office for Asia and the Pacific | In English | |
| ICAS | Institute for Corean-American Studies | In English | → Area studies |
| ICAS | International Convention of Asia Scholars | In English | → Organizations and associations → Area studies |
| ICB | Interim Change Bulletin | In English | |
| ICB | Interrupt Control Block | In English | |
| ICB | International Criminal Bar (www.bpi-icb.org) = CISL | Confédération Internationale des Syndicats Libres | In French = ICFTU | International Confederation of Free Trade Unions | In English = CIOSL | Confederación Internacional de Organizaciones Sindicales Libres | In Spanish = CIOSL | Confederação Internacional de Organizações Sindicais Livres | In Portuguese = BPI | Barreau Pénal International | In French |
In English | → Law, jurisprudence |
| ICB | International Centre of Biocybernetics | In English | → Research institutes → Computer science → Electronics |
| ICBC | IMAX Cargo Bay Camera | In English | |
| ICBM | Intercontinental Ballistic Missile | In English | → Military engineering |
| ICC | Intercomputer Channel | In English | → Networks, communication |
| ICC | Interface Control Chart | In English | → Human-computer interaction |
| ICC | Interface Control Contractor | In English | → Human-computer interaction |
| ICC | Interstate Commerce Commission | In English | → Trade |
| ICC | Intercomputer Communication | In English | → Networks, communication |
| ICC | International Computing Centre (www.unicc.org) = CICE | Centro Internacional de Cálculos Electrónicos | In Spanish = CIC | Centre International de Calcul | In French = CIC | Centro Internacional de Computação | In Portuguese |
In English | → Computer science → United Nations |
| ICC | Integrated Circuit(s) Cards | In English | → Electronics |
| ICC | International Association for Cereal Science and Technology | In English | → Associations → Agricultural sciences |
| ICC | International Chamber of Commerce (www.iccwbo.org) = CCI | Cámara de Comercio Internacional | In Spanish = CCI | Chambre de Commerce Internationale | In French = CCI | Câmara de Comércio Internacional | In Portuguese |
In English | → Organizations and associations → Trade |
| ICC | Internet Chess Club | In English | → Organizations and associations |
| ICC | International Criminal Court = CPI | Cour Pénale Internationale | In French |
In English | → Law, jurisprudence |
| ICCA | International Congress and Convention Association | In English | → Associations → Congresses |
| ICCAT | International Commission for the Conservation of Atlantic Tunas (www.iccat.es) | In English | → Nature → Fishing, hunting |
| ICCHP | International Conference on Computers Helping People with Special Needs | In English | → Congresses → Computer-based techniques |
| ICCP | Interface Coordination and Control Procedure | In English | |
| ICCPR | International Conference on Cultural Policy Research | In English | → Civilization, culture, progress → Politics |
| ICCR | Interdisciplinary Centre for Comparative Research in the Social Sciences = CIR | Centre Interdisciplinare de Recherche Comparative en Sciences Sociales | In French |
In English | → Social sciences |
| ICCR | Indian Council for Cultural Relations | In English | → Civilization, culture, progress |
| ICCR | Interfaith Center on Corporate Responsibility | In English | → Ethics |
| ICCWG | Intercenter Communication Working Group | In English | |
| ICD | Interface Control Document | In English | → Human-computer interaction |
| ICD | Interface Control Drawing | In English | → Human-computer interaction |
| ICD | Interface Control Documentation | In English | → Human-computer interaction |
| ICD | International Code Designator | In English | |
| ICD-O | International Classification of Diseases for Oncology | In English | → Bibliography → Oncology |
| ICDA | Integrated Cached Disk Array | In English | → Hardware |
| ICDAR | International Conference on Document Analysis and Recognition | In English | → Congresses → Document processing |
| ICDR | Incremental Critical Design Review | In English | |
| ICDS | Interface Control Document Schedule | In English | → Human-computer interaction |
| ICDU | Inertial Coupling Data Unit | In English | |
| ICE | Input Control Element | In English | |
| ICE | Instrument Checkout Equipment | In English | |
| ICE | Ideal Cabin Environment | In English | → Aeronautics, aircraft |
| ICEAPS | International Centre of Excellence in Asia Pacific Studies | In English | → Area studies |
| ICEIS | International Conference on Enterprise Information Systems | In English | → Congresses → Knowledge management → Data |
| ICEM | Intergovernmental Committee for European Migration | In English | → International relations → Migrations |
| ICES | International Council for the Exploration of the Seas (www.ices.inst.dk) | In English | → Organizations and associations → Marine research, oceanography |
| ICES | International Centre for Ethnic Studies | In English | → Ethnology |
| ICF | International Christian Fellowship (www.icf.ch) | In English | → Christianity |
| ICF | International Canoe Federation (www.canoeicf.com) | In English | → Organizations and associations → Sport, physical exercises |
| ICF | International Coach Federation (www.coachfederation.org) | In English | → Organizations and associations → 659 |
| ICF | Intracellular fluid | In English | → Physiology |
| ICF | Interface Control Function | In English | → Human-computer interaction |
| ICFTU | International Confederation of Free Trade Unions (www.icftu.org) = ICB, CISL, CIOSL, BPI (look above) |
In English | → Organizations and associations → Labour, labour economics |
| ICG | In-Flight Coverall Garment | In English | → Aeronautics, aircraft → Spaceflight engineering, astronautics |
| ICG | Institute for Career Guidance | In English | → Labour, labour economics |
| ICGA | IEEE (Institute of Electrical and Electronics Engineers) Computer Graphics Applications | In English | → Serial publications, periodicals → Graphical processing |
| ICH | International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use | In English | → Pharmacology, toxicology → Veterinary medicine |
| ICHA | Integrated Cargo Hazard Assessment | In English | |
| ICHMT | International Communications in Heat and Mass Transfer | In English | → Serial publications, periodicals → Thermodynamics |
| ICHO | Iran Cultural Heritage Organisation | In English | → Organizations and associations → Civilization, culture, progress |
| ICHR | Indian Council for Historical Research | In English | → Organizations and associations → History |
| ICHRDD | International Centre for Human Rights and Democratic Development (www.ichrdd.ca) = CIDPDD | Centre International des Droits de la Personne et du Développement Démocratique | In French |
In English | → Organizations and associations → Fundamental rights → Democracy |
| ICHRP | International Council on Human Rights Policy | In English | → Organizations and associations → Fundamental rights |
| ICHRPI | International Commission for the History of Representative and Parliamentary Institutions | In English | → Parliaments, representation → History |
| ICHSEA | International Conference on the History of Science in East Asia | In English | → Congresses → Mathematics and natural sciences → History |
| ICI | Interim Configuration Inspection | In English | |
| ICIAM | International Council for Industrial and Applied Mathematics | In English | → Mathematics |
| ICID | International Commission on Irrigation and Drainage | In English | → Organizations and associations → Agricultural sciences → Environmental technology, water supply, waste management |
| ICID | International Commission for Irrigation and Drainage = CIID | Commission Internationale pour les Irrigations et le Drainage | In French |
In English | → Organizations and associations → 627 → Agricultural sciences |
| ICIE | Institute for Communications and Information Engineering | In English | → Telecommunications → Computer science |
| ICIEC | Islamic Corporation for the Insurance of Investment & Export Credit | In English | → Banks → International economic cooperation |
| ICIS | Institute for Comparative and International Studies | In English | → International relations |
| ICiSM | IEEE (Institute of Electrical and Electronics Engineers) Circuits Systems Magazine | In English | → Serial publications, periodicals → Electronics |
| ICISS | International Commission on Intervention and State Sovereignty (www.iciss-ciise.gc.ca) = CONAP | Confederación de Nacionalidades Amazónicas del Perú | In Spanish = CONAP | Confederation of Amazonian Nationalities of Peru | In English = CONAP | Confédération des Nationalités Amazoniennes du Pérou | In French = CONAP | Confederação das Nações Amazônicas do Peru | In Portuguese = CIISE | Commission Internationale de l'Intervention et de la Souveraineté des États | In French |
In English | → International relations → United Nations |
| ICJ | International Court of Justice (www.icj-cij.org) = CIJ | Cour Internationale de Justice | In French = CIJ | Corte Internacional de Justicia | In Spanish = CIJ | Corte Internacional de Justiça | In Portuguese = CIJ | Cort Internacional de Justícia | In Catalan = MSD | Mezinárodní soudní dvůr | In Czech = IGH | Internationaler Gerichtshof | In German = ΔΔΔ | Διεθνές Δικαστήριο της Δικαιοσύνης | In Greek = IK | Internacia Kortumo | In Esperanto = ICJ | 국제사법재판소 | In Korean = TTT | Tarptautinis Teisingumo Teismas | In Lithuanian = MTS | Międzynarodowy Trybunał Sprawiedliwości | In Polish = MSD | Medzinárodný súdny dvor | In Slovak = МСП | Међународни суд правде | In Serbian = MSP | Međunarodni sud pravde | In Serbo-Croatian |
In English | → International relations → Law, jurisprudence |
| ICL | Imperial College London | In English | → Higher education, universities |
| ICL | Interface Control Layout | In English | → Human-computer interaction |
| ICLARM | International Centre for Living Aquatic Resources Management | In English | → Fishing, hunting |
| ICLC | Interlab Cell Line Collection (www.iclc.it) | In English | → Cytology → Biotechnology |
| ICLD | Interlab Cell Line Database | In English | → Cytology → Biotechnology |
| ICLP | Institute of Chinese Literature and Philosophy | In English | → Research institutes → Philosophy, psychology → Literature |
| ICM | Intergovernmental Committee for Migration | In English | → International relations → Migrations |
| ICM | Instrumentation and Communication Monitor | In English | |
| ICM | Integrated Cost Module | In English | → Prices |
| ICM | Inner Cell Mass | In English | → Biological sciences |
| ICME | Institute of Cast Metals Engineers | In English | → Metallurgy |
| ICMI | Inductive Components Manufacturing Inc. (www.icmiinc.com) | In English | → Electrical engineering |
| ICMI | International Conference on Multimodal Interfaces | In English | → Congresses → Human-computer interaction |
| ICMI | International Customer Management Institute (www.incoming.com) | In English | → Management |
| ICMI | International Commission on Mathematical Instruction (www.mathunion.org/ICMI/) | In English | → Organizations and associations → Mathematics → Education |
| ICMJE | International Committee of Medical Journal Editors (www.icmje.org) | In English | → Serial publications, periodicals → Medicine |
| ICMP | Internet Control Message Protocol | In English | → Internet |
| ICMR | Indian Council for Medical Research | In English | → Medicine |
| ICMS | Indirect Cost Management System | In English | → Prices |
| ICMS | International College of Management Sydney | In English | → Specialized or (poly)technical colleges → Computer science |
| ICMS | International Committee on Museum Security | In English | → Museums |
| ICMT | Intercontract Material Transfer | In English | |
| ICN | Intercomputer Network | In English | → Networks, communication |
| ICN | Interface Change Notice | In English | |
| ICN | Inspectorate of Civil Navigation | In English | → Public administration, government → Transport and postal services |
| ICN | International Conference on Nutrition = CIN | Conferencia Internacional sobre Nutrición | In Spanish = CIN | Conférence Internationale sur la Nutrition | In French = CIN | Conferência Internacional sobre Nutrição | In Portuguese |
In English | → Congresses → Nutrition |
| ICO | Integrated Checkout | In English | |
| ICO | Integrated-Communication Officer | In English | |
| ICOC | Indonesia Council Open Conference | In English | → Organizations and associations |
| ICOLD | International Commission on Large Dams (www.icold-cigb.org) | In English | → Organizations and associations → 627 |
| IComM | IEEE (Institute of Electrical and Electronics Engineers) Communications Magazine | In English | → Serial publications, periodicals → Networks, communication → Telecommunications |
| ICOPHIL | International Conference on Philippine Studies | In English | → Congresses → Area studies |
| ICORD | International Collaboration on Repair Discoveries | In English | → Organizations and associations → Neurology → Traumatology |
| ICOS | Integrated Court Operations System | In English | |
| ICOS | Integrated Cavity Output Spectroscopy | In English | → Analytical chemistry |
| ICOS | Integrated Cargo Operating Software | In English | → Software → Transport and postal services |
| ICOS | Inducible Costimulator | In English | → Biological sciences |
| ICOS | Integrated Casino Operating System | In English | |
| ICOS | Integrated Communications Organizing Standard | In English | → Standardization → Telecommunications |
| ICOS | Integrated Compact Oil Seal | In English | |
| ICOS | Integrated Coastal Observation System | In English | |
| ICOTT | International Congress of Official Tourist Traffic Associations | In English | → Organizations and associations → Tourism |
| ICOUR | Irrigation Company for the Upper Regions | In English | → 627 → Agricultural sciences |
| ICP | Insane Clown Posse | In English | → Music |
| ICP | Intracranial pressure | In English | → Physiology → Neurology |
| ICP | Inductively Coupled Plasma | In English | → Plasma physics |
| ICP | International Center of Photography | In English | → Photography |
| ICP | Iterative Closest Point | In English | |
| ICP | International Comparison Program | In English | → Economics |
| ICP | ICS Control Program | In English | |
| ICP | Indicator Control Panel | In English | |
| ICP | Interface Change Proposal | In English | → Networks, communication |
| ICP | Inventory Control Point | In English | |
| ICP | Interface Control Panel | In English | → Networks, communication |
| ICP-MS | Inductively Coupled Plasma Mass Spectrometry | In English | → Plasma physics → Chromatography, mass spectrography |
| ICPDR | International Commission for the Protection of the Danube River | In English | → Organizations and associations → Nature and society → 627 |
| ICPEN | International Consumer Protection and Enforcement Network | In English | |
| ICPO | Irrevocable Corporate Purchase Order | In English | → Trade → 34775 |
| ICPO | Institute of Cytology & Preventive Oncology | In English | → Research institutes → Cytology → Oncology |
| ICPO | International Criminal Police Organization | In English | → Organizations and associations → Police |
| ICPO | Irrevocable Commission Payment Order | In English | → Trade |
| ICPR | Indian Council of Philosophical Research | In English | → Organizations and associations → Philosophy, psychology |
| ICPS | International Conference on the Physics of Semiconductors | In English | → Congresses → Electricity, magnetism, electromagnetism → 539 → Electrical engineering |
| ICR | Interface Compatibility Record | In English | → Networks, communication |
| ICR | Instruction Change Request | In English | |
| ICR | Inductance, Capacitance, and Resistance | In English | → Physics → Electrical engineering |
| ICR | Intelligent Character Recognition | In English | → Writing systems → Computer-based techniques |
| ICRA | Internet Content Rating Association | In English | → Internet → Organizations and associations |
| ICRA | International Conference on Robotics and Automation | In English | |
| ICRAT | International Conference on Research in Air Transportation | In English | → Congresses → Transport and postal services |
| ICRB | Interface Change Review Board | In English | → Networks, communication |
| ICRC | International Committee of the Red Cross (www.icrc.org) = CICR | Comité Internacional de la Cruz Roja | In Spanish = CICR | Comité International de la Croix-Rouge | In French = CICV | Comitê Internacional da Cruz Vermelha | In Portuguese = МККК | Международный комитет Красного Креста | In Russian = SSKK | Starptautiskā Sarkanā Krusta Komiteja | In Latvian = CICR | Comitato Internazionale della Croce Rossa | In Italian = ICRC | 적십자 국제 위원회 | In Korean = CICR | Comitè Internacional de la Creu Roja | In Catalan = CICR | Comitât entèrnacionâl de la Crouèx-Roge | In Franco-Provençal |
In English | → Organizations and associations → Medicine |
| ICRISAT | International Crops Research Institute for the Semi-Arid Tropics | In English | → Organizations and associations → Agricultural sciences |
| ICRP | International Commission on Radiological Protection | In English | → Nuclear technology |
| ICRP | International Council on Radiation Protection | In English | → International relations |
| ICRU | International Commission on Radiation Units and Measurements = CIUMR | Comisión Internacional de Unidades y Medidas Radiológicas | In Spanish = CIUMR | Commission Internationale des Unités et des Mesures de Radiation | In French = CIUMR | Comissão Internacional de Unidades e Medidas Radiação | In Portuguese |
In English | → Standardization → Nuclear technology |
| ICS | Intercommunication System | In English | → Networks, communication → Telecommunications |
| ICS | Instrumentation Control System | In English | |
| ICS | Interpretive Computer Simulator | In English | → Computer simulation |
| ICS | Interface Control Specification | In English | → Human-computer interaction |
| ICS | Interphone Control Station | In English | → Telecommunications |
| ICS | Intelligent Control Systems | In English | → Engineering, technology |
| ICS | India China School | In English | → Education |
| ICS | International Classification for Standards | In English | → Standardization |
| ICS | International Commission on Stratigraphy | In English | → Organizations and associations → Stratigraphy |
| ICS | International Child Support | In English | → Organizations and associations |
| ICSA | International Cultic Studies Association | In English | → Associations → Social sciences |
| ICSC | International Civil Service Commission = CAPI | Comisión de Administración Pública Internacional | In Spanish = CFPI | Commission de la Fonction Publique Internationale | In French = CAPI | Comissão de Administração Pública Internacional | In Portuguese |
In English | → Public administration, government → United Nations |
| ICSC | International Council of Shopping Centers | In English | → Organizations and associations → Trade |
| ICSE | Impact of Computing in Science and Engineering | In English | → Serial publications, periodicals → Computer science → Mathematics and natural sciences → Engineering, technology |
| ICSEAD | International Centre for the Study of East Asian Development | In English | → Development |
| ICSID | International Centre for Settlement of Investment Disputes (www.worldbank.org/icsid/) = CIADI | Centro Internacional de Arreglo de Diferencias relativas a Inversiones | In Spanish = CIRDI | Centre International pour le Règlement des Différends relatifs aux Investissements | In French |
In English | → International economic cooperation → Finance |
| ICSM | IEEE (Institute of Electrical and Electronics Engineers) Computer Systems Magazine | In English | → Serial publications, periodicals → Hardware |
| ICSN | Indonesian Conflict Studies Network | In English | → Polemology |
| ICSSR | Indian Council of Social Science Research | In English | → Organizations and associations → Social sciences |
| ICSTI | International Council for Scientific and Technical Information | In English | → Libraries → Mathematics and natural sciences → Engineering, technology |
| ICSU | International Council of Scientific Unions | In English | → Organizations and associations → Mathematics and natural sciences |
| ICSV | International Congress on Sound and Vibration | In English | → Congresses → Acoustics |
| ICT | International Campaign for Tibet | In English | |
| ICT | Information and Communications Technology = TIC | Tecnologías de la Información y la Comunicación | In Spanish = IKT | Informations- und Kommunikationstechnologie | In German = TIC | Technologies de l'Information et de la Communication | In French = IKT | Informations- og kommunikationsteknologi | In Danish = IKT | Inligtings- en kommunikasietegnologie | In Afrikaans = ICT | Informatie- en Communicatietechnologie | In Dutch = TMK | Teknologi Maklumat dan Komunikasi | In Malay |
In English | → Computer science → Telecommunications |
| ICT | Interface Control Tooling | In English | → Human-computer interaction |
| ICT | Influence Coefficient Test | In English | |
| ICTAF | Interdisciplinary Center for Technological Analysis & Forecast | In English | → Energy economics |
| ICTAF | Interdisciplinary Center for Technology Analysis & Forecasting | In English | → Engineering, technology |