| IWTA | Idaho Wheelchair Tennis Association 
| Others |
| IWTA | Inner West Tennis Academy
| Others |
| IWTA | Insincere Wing Tsun Amnesia
| Others |
| IWTA | Inter Work Transfer Authorization
| Others |
| IWTA | International Water Technology Association
| Others |
| IWTA | International Waterpolo Tournament Amsterdam
| Others |
| IWTA | International Wheelchair Tennis Association
| Others |
| IWTA | International Wireless Telecommunications Association
| Others |
| IWTA | International Workshop on Teaching Analytics
| Others |
| IWTA | Iowa Water Trails Association
| Others |
| IWTA | Irish Water Treatment Association
| Others |