| Acronym | Definition |
|---|
| HIWG➣Humanitarian Issues Working Group (UN High Commissioner for Refugees; Geneva, Switzerland) |
| HIWG➣History of the Imperium Working Group (Traveller roleplaying game fan group) |
| HIWG➣Holocene Impact Working Group (climate change) |
| HIWG➣Health Insurance Working Group |
| HIWG➣Hawaii Wing (Civil Air Patrol) |
| HIWG➣Honouring Indigenous War Graves, Inc. (Australia) |