- AJ stands for Acting Jack (Acting Sergeant; Army)
- AJ stands for Active Jamming
- AJ stands for Adjustable Spanner (British; wrench)
- AJ stands for Administrative Judge
- AJ stands for Aide Juridictionnelle (French: Legal Aid)
- AJ stands for Air Jamaica (airline)
- AJ stands for Air Jordan (shoe)
- AJ stands for Albergue Juvenil José Gilberto Flores Vides (Jose Gilberto Vides Flores Youth Lodge, Guatemala)
- AJ stands for Albert James (Foyt)
- AJ stands for Alberta Judgements (Canada)
- AJ stands for Albuquerque Journal (newspaper)
- AJ stands for Alexander James McLean (Backstreet Boys)
- AJ stands for Al-Jazeera (Middle East TV Network)
- AJ stands for Allen Jones (wrestler)
- AJ stands for Alpinisme Juvénile (French mountaineering group)
- AJ stands for Amber Jack
- AJ stands for Andrew Jackson (7th US President)
- AJ stands for Angelina Jolie (actress)
- AJ stands for Animal Jam (online educational playground)
- AJ stands for Ankle Jerk
- A/J stands for Anti/Jam or Anti/Jamming
- AJ stands for Anti-Jam
- AJ stands for Anti-Jamming
- A/J stands for Anti-Jamming (radar)
- AJ stands for Anup Jalota (Indian singer)
- AJ stands for Apostles of Jesus (Religious)
- AJ stands for Apple Juice
- AJ stands for Applejack (My Little Pony character)
- AJ stands for Apricot Juice
- AJ stands for Arabtech Jardaneh (various locations)
- AJ stands for Armani Jeans
- AJ stands for Arrow Jazz (radio channel)
- AJ stands for Articulation Joint
- AJ stands for Ask Jeeves
- AJ stands for Assembly Jig
- AJ stands for Association de La Jeunesse (French youth soccer)
- AJ stands for Astronomical Journal
- AJ stands for Atari Jaguar
- AJ stands for Auberge Jeunesse (French: youth hostel)
- AJ stands for Audax Japan
- AJ stands for Aunt Jemima
- AJ stands for Awesome Job
- AJ stands for Azerbaydzhan
A/J