ARL
- ARL 44
- ARL3
- ARL8A
- ARL8B
- Admiralty Research Laboratory
- Aero Research Limited
- Air Resources Laboratory
- Airport Rail Link (Bangkok)
- Albanian Rugby League
- Animal Rescue League of Western Pennsylvania
- Argyll
- Arlesey railway station
- Arly Airport
- Armour Refrigerator Line
- Arriva Rail London
- Association of Research Libraries
- Auckland Rugby League
- Australian Rugby League
- Authority revocation list
- Autolinee Regionali Luganesi
- Chapman code
- List of auxiliaries of the United States Navy
- Pennsylvania State University Applied Research Laboratory
- United States Army Research Laboratory