| IA | Import Administration, U.S. Department of Commerce |
| IADB (or IDB) | Inter-American Development Bank |
| IAEA | International Atomic Energy Agency |
| IAWG | Inter-Agency Working Group |
| IBRD | International Bank for Reconstruction and Development (World Bank) |
| IC | Industry Committee of the OECD |
| ICA | International Coffee Agreement |
| ICA | International Cocoa Agreement |
| ICA | International Commodity Agreement |
| ICAO | International Civil Aviation Organization |
| ICB | International Competitive Bidding |
| ICC | International Chamber of Commerce |
| ICITO | Interim Commission of the International Trade Organization |
| ICO | International Coffee Organization |
| ICSID | International Center for the Settlement of Investment Disputes |
| IDA | International Development Association |
| IDB (or IADB) | Inter-American Development Bank |
| IEA | International Energy Agency |
| IEC | International Electrotechnical Commission |
| IEEPA | International Emergency Economic Powers Act |
| IESC | International Executive Service Corps |
| IF | Integrated Framework |
| IFTRTA | Integrated Framework for Trade-Related Technical Assistance |
| IFTF | Integrated Framework Trust Fund |
| IFWG | Integrated Framework Working Group |
| IFAD | International Fund for Agricultural Development |
| IFC | International Finance Corporation |
| IFI | International Finance Institution |
| IIC | Inter-American Investment Corporation |
| IIPA | International Intellectual Property Alliance |
| ILO | International Labor Organization |
| IMF | International Monetary Fund |
| IMO | International Maritime Organization |
| INCOTERMS | International Commercial Terms |
| INR | Initial Negotiating Right |
| INRA | International Natural Rubber Agreement |
| INRO | International Natural Rubber Organization |
| INTELSAT | International Telecommunications Satellite Organization |
| IOR-ARC | Indian Ocean Rim Association for Regional Cooperation |
| IOS | International Organization for Standardization |
| IP | Intellectual property |
| IPAC | Industry Policy Advisory Committee (United States) |
| IPC | Integrated Program for Commodities |
| IPR | Intellectual property rights |
| IR | Integrated Response |
| ISA | International Sugar Agreement |
| ISAC | Industry Sector Advisory Committee (United States) |
| ISO | International Standards Organization |
| ITA | International Trade Administration, U.S. Department of Commerce |
| ITA | International Tin Agreement |
| ITA | Information Technology Agreement |
| ITAR | International Traffic in Arms Regulations |
| ITC | International Trade Commission (United States) |
| ITC | International Trade Center, UNCTAD/WTO |
| ITO | International Trade Organization |
| ITU | International Telecommunication Union |
