| IIU | Illinois Independent Umpires 
| Others |
| IIU | Imagery Interpretation Unit
| Others |
| IIU | Immigration Impact Unit
| Others |
| IIU | Impact and Innovation Unit
| Others |
| IIU | Independent Integrity Unit
| Others |
| IIU | Independent Investigation Unit
| Others |
| IIU | Independent Investigation Unit of manitoba
| Others |
| IIU | Indus International University
| Others |
| IIU | Informatics Intergration Unit
| Others |
| IIU | Information Investigations Unlimited, Inc.
| Others |
| IIU | Infrastructure Implementation Unit
| Others |
| IIU | Initial Intervention Unit
| Others |
| IIU | Insurance Institute of Uganda
| Others |
| IIU | Integrated Input Unit
| Others |
| IIU | Internal Investigations Unit
| Others |
| IIU | Internal Investigations Unitr
| Others |
| IIU | Internal Investigative Unit
| Others |
| IIU | International Investment and Underwriting
| Others |
| IIU | International Investment Underwriting
| Others |
| IIU | International Islamic University
| Others |
| IIU | International Islamic University, Malaysia
| Others |
| IIU | Internet Islamic University
| Others |
| IIU | Isles International University
| Others |
| IIU | Israeli Internet Underground
| Others |