| Acronym | Definition |
|---|
| OpBA | Opponents Batting Average (baseball) |
| OpBA | Offshore Powerboat Association |
| OpBA | Offshore Power Boat Association |
| OpBA | Operations Per Based Aircraft |
| OpBA | Ohio Poultry Breeders Association |
| OpBA | Ontario Public Buyers Association, Inc. |
| OpBA | Ontario Professional Basketball Association (Canada) |
| OpBA | Oceania Pocket Billiard Association |
| OpBA | Ohio Patrolmen's Benevolent Association |
| OpBA | Ogden Police Benefit Association (Utah) |
| OpBA | Ontario Pension Benefits Act (Canada) |
| OpBA | Old Pueblo Business Alliance |
| OpBA | Ohio Proficiency-Based Assessment |
| OpBA | Orlando Police Benevolent Association (Florida) |
| OpBA | Old Pueblo Bass Anglers (Tucson, AZ) |
| OpBA | Ohio Pawnbrokers Association |
| OpBA | Ontario Pinzgauer Breeders Association (Canada) |
| OpBA | Order of the Palm of the Barony of Atenveldt |
| OpBA | Occupational Pension Benefits Act (Barbados) |
| OpBA | Open Barrel |