| Acronym | Definition |
|---|
| OAT | Operational Assessment Team |
| OAT | Overseas Adventure Travel (Grand Circle Travel) |
| OAT | Of All Time |
| OAT | Operating Ambient Temperature |
| OAT | Optometry Admission Test |
| OAT | Overall Test |
| OAT | Outside Air Temperature |
| OAT | Obligations Assimilables du Trésor (French treasury bond) |
| OAT | Oxygen Atom Transfer |
| OAT | Operational Acceptance Testing (product performance) |
| OAT | Office for the Advancement of Telehealth |
| OAT | Ornithine Aminotransferase (deficiency) |
| OAT | Ohio Achievement Tests |
| OAT | Operational Air Traffic |
| OAT | Operational Acceptance Test |
| OAT | Oxford Aviation Training |
| OAT | Office of Aerospace Technology |
| OAT | Organic Additive Technology (car engines coolant) |
| OAT | Office of Appropriate Technology (California) |
| OAT | Open Access Transmission |
| OAT | Oxyacetylene Torch |
| OAT | Otherwise Applicable Tariff (regulated utilities rate schedules) |
| OAT | On Another Topic |
| OAT | Offshore Assault Team |
| OAT | Oxide-Aligned Transistor |
| OAT | Optional Application Tape |
| OAT | Orbit Adjust Thruster |
| OAT | Opposite Angle Theorem |
| OAT | Orleans Arena Theatre (Orleans, MA; later, Orleans Academy Theatre) |
| OAT | On-Air Test |
| OAT | Optimal Adaptive Transmission |
| OAT | Optically post-Amplified Transmitter (Bellcore) |
| OAT | On Approved Terms |
| OAT | Oligo-Asthéno-Tératospermie (French; male infertility disorder) |
| OAT | Office of Applied Technology |
| OAT | Organic Acid Type (coolant) |
| OAT | Optically Amplified Transmission (Lucent) |