| Abbreviation | Definition |
|---|---|
| ISEA | Indiana Student Education Association |
| ISEA | Inland Seas Education Association |
| ISEA | International Safety Equipment Association |
| ISEA | International Sports Engineering Association |
| ISEA | Irish Solar Energy Association |
| ISFA | Illinois State Florist Association |
| ISFA | International Salmon Farmers Association |
| ISFA | International String Figure Association |
| ISFA | International Surface Fabricators Association |
| ISGA | International Social Games Association |
| ISGA | International Sport Grappling Association |
| ISIA | Illinois Self Insurers Association |
| ISIA | Indiana Self Insurers Association |
| ISIA | International Serum Industry Association |
| ISIA | International Ski Instructors Association |
| ISIA | Irish Security Industry Association |
| ISKA | International Shotokan Karate Association |
| ISKA | International Sport Kickboxing Association |
| ISKA | International Spouses of Koreans Association |
| ISKA | Irish Sea Kayaking Association (Ireland) |