AST
- ACT Scaling Test
- AST (exam)
- AST (publisher)
- AST Research
- AST SpaceMobile
- Abstract syntax tree
- Abwehr
- Advanced Skills Teacher
- Air Service Training
- Alaska Standard Time
- Alaska State Troopers
- Aldershot GO Station
- Allied Security Trust
- Alternating series test
- Alternative set theory
- American School in Taichung
- American School of Tangier
- American School of Tegucigalpa
- American School of Tripoli
- Anamorphic stretch transform
- Andrew S. Tanenbaum
- Antibiotic sensitivity testing
- Application security
- Arabia Standard Time
- Arsenal Supporters' Trust
- Aspartate transaminase
- Assured shorthold tenancy
- Astana Pro Team
- Asti
- Aston railway station
- Astoria Regional Airport
- Asturian language
- Asynchronous system trap
- Atlantic School of Theology
- Atlantic Standard Time
- Attention schema theory
- Augstsprieguma tīkls
- Avalanche Skills Training
- Aviation Survival Technician
- Chadian Social Action
- Conroe ISD Academy of Science and Technology
- Georg Anton Friedrich Ast
- Office of Commercial Space Transportation
- Pat Ast
- Time in Antigua and Barbuda