| Acronym | Meaning |
| OA | Objective Area |
| OA | Offensive Action |
| OA | Office Action |
| OA | Office of Administration |
| OA | Office of AIDS (California) |
| OA | Office of Applications |
| OA | Office of Audits |
| OA | Office of the Administrator |
| OA | Open Architecture |
| OA | Operating Authorization |
| OA | Operational Architecture |
| OA | Operational Area |
| OA | Operational Assessment |
| OA | Operational Assist/Assembly |
| OA | Operational Assistance |
| OA | Operational Availability |
| OA | Operations Aerographer |
| OA | Operations Agreement (NASA) |
| OA | Operations Analyst |
| OA | Orbital Analyst |
| OA | Order of Australia |
| OA | Organization and Administration |
| OA | Organizational Assessment |
| OA | Over Aged |
| OA | Overhead Approach |
| OA | Oversight & Performance Assurance |