| Abbreviation | Definition |
|---|---|
| OD | Oculus Dexter |
| ODBL | Orthopaedic and Developmental Biomechanics Laboratory |
| ODV | Optimised Deprival Value |
| OFCL | Optical Fiber Communication Laboratory |
| OFD | Object-Film Distance |
| OFS | Organic Fiber Sterilization |
| OGTT | Oral Glucose Tolerance Test |
| OKG | Ornithine Alpha-Ketoglutarate |
| OKT | ortho-kung T (cell) |
| OLA | Optical Laboratories Association |
| OLAM | Office of Laboratory Animal Medicine |
| OLAW | Office of Laboratory Animal Welfare |
| OLRT | Oxoid Listeria Rapid Test |
| OLS | Office of Laboratory Services |
| OLTT | Oral Lipid Tolerance Test |
| OM | Outer Membrane |
| OM | Outer Mitochondrial |
| OMCL | Official Medicines Control Laboratories |
| OMCL | Official Medicines Control Laboratory |
| OMRF | Oklahoma Medical Research Foundation |