- ARE(Atelier de Construction Roanne)
- AREA(Additional Reinforcement Enrichment Activities)
- AREC(Air Resource Element Coordinator)
- ARENA(Area Recreation, Entertainment, Nutrition, and Association)
- ARES(Amateur Radio Emergency Service)
- AREST(anticipate, redifferentiate, empower, supervise and assess)
- ARESV(analysis of reservoir)
- ARETS(Armour Remote Target System)
- AREUEA(The American Real Estate and Urban Economics Association)
- ARF(ASEAN Regional Forum)
- ARFF(Achievement, Respect, Fun, And Freedom)
- ARFFC(Alzheimer's Research Foundation, Fisher Center)
- ARFOR(Army Forces)
- ARFORGEN(Army force generation)
- ARFPC(Army Reserve Forces Policy Committee)
- ARFS(aggression risk factors survey)
- arg(Aragonese language (ISO 639-2 code))
- ARGH(Autism Rights Group Highland)
- ARGO(Automatic Ranging Grid Overlay)