| Abbreviation | Definition |
|---|---|
| ITT | Israeli Technical Teledyne |
| ITTC | International Theatrical Truss Corporation |
| ITTC | Italian Tools Technology Company |
| IUAQ | Iraqi Unity Association Queensland |
| IUB | Indiana United Bancorp |
| IUCI | Informal Urban Communities Initiative |
| IUCM | Izquierda Unida Comunidad de Madrid |
| IUD | Independent United Distributors |
| IUF | International Union of Food, Agricultural, Hotel, Restaurant, Catering, Tobacco, and Allied Workers' Associations |
| IUH | Integrated Utility Holding |
| IUI | Information Unlimited Inc |
| IUK | Imagineering United Kingdom |
| IUL | Imagination, Un-Ltd. |
| IUL | Interactive Urban Landscapes |
| IUL | Internet Unlimited, Ltd. |
| IUM | Arbeitskreis Innovationsmanagement und Marketing |
| IUM | Interocean Ugland Management Corporation |
| IUM | Investors Underwriting Managers, Inc. |
| IUV | Interstate Underground Warehouse |
| IUW | Interstate Underground Warehouse |