| International Scout and Guide Fellowship | International Scout and Guide Fellowship |
| International Securities Identifying Number | ISIN |
| International Security Assistance Force | International Security Assistance Force |
| International Sign | Gestuno |
| International Six Days Enduro | International Six Days Enduro |
| International Skating Union | Internationale Schaatsunie |
| International Ski Federation | Fédération Internationale de Ski |
| International Social Survey Programme | Internationaal Sociaal Survey Programma |
| International Society for Krishna Consciousness | Hare Krishna-beweging |
| International Somalia Contact Group | International Somalia Contact Group |
| International Space Station | Internationaal ruimtestation ISS |
| International Standard Atmosphere | Standaardatmosfeer |
| International Standard Audiovisual Number | Internationaal Standaard Audiovisueel Nummer |
| International Standard Book Number | Internationaal Standaard Boeknummer |
| International Standard Classification of Occupations | ISCO |
| International Standard Music Number | ISMN |
| International Standard Recording Code | ISRC |
| International Standard Serial Number | ISSN |
| International Statistical Classification of Diseases and Related Health Problems | International Statistical Classification of Diseases and Related Health Problems |
| International Student Identity Card | International Student Identity Card |
| International style | Internationale Stijl |
| International Swimming Federation | Fédération Internationale de Natation |
| International Symbol of Access | Internationaal Toegankelijkheidssymbool |
| International System of Units | Système International |
| International Taekwondo Federation | International Taekwondo Federation |
| International Talk Like a Pirate Day | Internationale praat als een piraat dag |
| International Tchaikovsky Competition | Internationale Tsjaikovskiwedstrijd |
| International Telecommunication Union | Internationale Telecommunicatie-unie |
| International Tennis Federation | International Tennis Federation |
| International Tennis Hall of Fame | Tennis Hall of Fame |
| International Trade Union Confederation | Internationaal Vakverbond |
| International Union of Catholic Esperantists | Internacia Katolika Unuiĝo Esperantista |
| International Union of Geological Sciences | International Union of Geological Sciences |
| International Union of Pure and Applied Chemistry | IUPAC |
| International Union of Pure and Applied Chemistry nomenclature | IUPAC-nomenclatuur |
| International Union of Railways | Union Internationale des Chemins de fer |
| International Union of Socialist Youth | International Union of Socialist Youth |
| International unit | Internationale Eenheid |
| International Virtual Aviation Organization | International Virtual Aviation Organization |
| International Whaling Commission | Internationale Walvisvaartcommissie |
| International Workers Association | Eerste Internationale |
| International Youth Congress of Esperanto | Internationaal Jongerencongres |
| Internationale | Internationale |
| Internationale Automobil-Ausstellung | Internationale Automobilausstellung |
