| International Orienteering Federation | Federazione Internazionale di Orientamento |
| International Peace Bureau | Bureau international permanent de la paix |
| International Phonetic Alphabet | alfabeto fonetico internazionale |
| International Phonetic Association | International Phonetic Association |
| International Physicians for the Prevention of Nuclear War | International Physicians for the Prevention of Nuclear War |
| international politics | politica internazionale |
| International Red Aid | Soccorso Rosso Internazionale |
| International Red Cross and Red Crescent Movement | Croce Rossa e Mezzaluna Rossa Internazionale |
| international relations | relazioni internazionali |
| International Rugby Hall of Fame | International Rugby Hall of Fame |
| international safety | sicurezza internazionale |
| International Sailing Federation | ISAF |
| International Science Olympiad | Olimpiadi scientifiche |
| International Scout and Guide Fellowship | International Scout and Guide Fellowship |
| International Security Assistance Force | International Security Assistance Force |
| International Ski Federation | Federazione Internazionale Sci |
| International Society for Krishna Consciousness | Associazione Internazionale per la Coscienza di Kṛṣṇa |
| International Space Station | Stazione Spaziale Internazionale |
| International Standard Audiovisual Number | International Standard Audiovisual Number |
| International Standard Bibliographic Description | International Standard Bibliographic Description |
| International Standard Book Number | Codice ISBN |
| International Standard Classification of Education | ISCED |
| International Standard Classification of Occupations | ISCO |
| International Standard Serial Number | ISSN |
| international standardisation | standardizzazione internazionale |
| International style | Movimento Moderno |
| International Swimming Federation | Fédération Internationale de Natation |
| International System of Units | Sistema internazionale di unità di misura |
| International Tchaikovsky Competition | Concorso Internazionale Čajkovskij |
| International Telecommunication Union | Unione Internazionale delle Telecomunicazioni |
| International Tennis Federation | Federazione Internazionale Tennis |
| International Tennis Hall of Fame | International Tennis Hall of Fame |
| international trade | commercio internazionale |
| international transaction | transazione internazionale |
| International Tribunal for the Law of the Sea | Tribunale Internazionale della Legge del Mare |
| International Truck of the Year | International Truck of the Year |
| International Union of Pure and Applied Chemistry | IUPAC |
| International Union of Railways | Union Internationale des Chemins de Fer |
| International Union of Socialist Youth | International Union of Socialist Youth |
| International Universal Recycling Codes | Codici universali internazionali di riciclaggio |
| international watercourse | corso d'acqua internazionale |
| International Whaling Commission | Commissione internazionale per la caccia alle balene |
| International Workers Association | Asociación Internacional de los Trabajadores |
| International Year of the Child | Anno Internazionale del Bambino |
| International Zetetic Challenge | International Zetetic challenge |
| internationalism | internazionalismo |
| Internationalization and localization | Internazionalizzazione e localizzazione |
| internationalize | internazionalizzare |
| internationally | a livello internazionale |
| internationally important ecosystem | ecosistema di importanza internazionale |
| interne | interno |
| internecine | di reciproca distruzione |
