- AX stands for (USN Rating) Aviation Antisubmarine Warfare Technician
- a-X stands for 1-Allyl-Xanthosine
- AX stands for Acceptance Requirements Index
- AX stands for Account Register
- AX stands for Accumulator
- AX stands for Agility Excellent (AKC title)
- A-X stands for Ajax, Ontario
- AX stands for Alpha Chi National College Honor Society (est. 1922)
- AX stands for Alpha Chi Omega (sorority)
- AX stands for American Express Company (credit card type)
- AX stands for Amman Exchange Co.
- AX stands for Analyst Executive
- AX stands for Anger-Expression Inventory
- AX stands for Anime Expo (animation convention)
- AX stands for Anion Exchanger
- AX stands for Arcade Extreme (game)
- AX stands for Architecture Extended
- AX stands for Arenacross (motor sports)
- AX stands for Armani Exchange
- AX stands for Assess/Assessment
- AX stands for Atlantic Coast Line Railroad Company
- AX stands for Auto Cross
- AX stands for Automatic Transmission
- AX stands for Auxiliary Systems
- AX stands for AUXOP (AUXMIS)
- ax stands for Axillary (armpit)
- AX stands for Axiom
- AX stands for Axis
- AX stands for Concept for Long Range Advanced Missile
- AX stands for X-Axis Acceleration
AX