BTA
- BTA Bank
- Baltimore Transit Alliance
- Bangsamoro Transition Authority
- Basic Trading Area
- Becoming the Archetype
- Benzotriazole
- Bertoua Airport
- Bicycle Transportation Alliance
- Bilateral trade agreement
- Biological Terrain Assessment
- Black Theatre Alliance
- Blair Municipal Airport
- Bluetooth
- Board of Tax Appeals
- Bolshoi Teleskop Azimutalnyi
- Botswana Telecommunications Authority
- British Tourist Authority
- British Triathlon Association
- Bulgarian News Agency
- Business Technology Association
- Business Transformation Agency
- Butyric acid
- Enemy Mine (film)