| Abbreviation | Definition |
|---|---|
| BARYC | Bay Area Regional Youth Circuit |
| BAS | Bay Area Slashers |
| BASA | Bay Area Soccer Association |
| BASE | Buildings, Antennas, Spans, and Earth |
| BASH | Bay Area Street Hockey |
| BASIC | Badminton And Swimming Including Cycling |
| BASK | Bay Area Sea Kayakers |
| BASS | Bass Anglers Sportsman Society |
| BASS | BASS Anglers Sportsmans Society |
| BASS | Bass Anglers Sportsmen Society |
| BASS | Boston Area Slalom Sessions |
| BASS | The Bass Angler Sportsman S |
| BASW | Best American Sports Writing |
| BAT | Bowl-A-Thon |
| BATL | Backyard Axe Throwing League |
| BATS | Boys After Testicle Sacks |
| BAV | Baarnse Atletiek Vereniging |
| BAV | Badminton Academy of Victoria, Melbourne, Australia |
| BAV | Boston Area Volleyball |
| BAVG | Batting Average |