| Acronym | Definition |
|---|
| OSL | Observed Safe Level |
| OSL | Oceanographic Systems Laboratory |
| OSL | Off Scale Low (NASA) |
| OSL | Office of Student Life |
| OSL | Officer of the Order of St. Lazarus |
| OSL | On Scene Leader |
| OSL | On-Site Laboratory |
| OSL | One Sexy Lady |
| OSL | OnGameNet Star League (Korean pro-gaming competition) |
| OSL | Open Source Lab |
| OSL | Open Source License |
| OSL | Open Space Laboratory (Tsukuba Research Center, Japan) |
| OSL | Open-Short-Load (electronic calibration) |
| OSL | Operational Safety Limit |
| OSL | Operational Site Layout |
| OSL | Operations Service Leader |
| OSL | Optical Stimulated Luminescence |
| OSL | Orbiting Solar Laboratory |
| OSL | Orbiting Space Laboratory |
| OSL | Order of St Luke the Physician |
| OSL | Oregon Short Line Railroad |
| OSL | Oregon State Library |
| OSL | Oslo, Norway - Gardermoen (Airport Code) |
| OSL | Oud Strijders Legioen (Dutch) |
| OSL | Outside Length |
| OSL | Over the Side Launch (tube launch torpedo) |
| OSL | Overlay Service Layer |
| OSL | Open Software License |
| OSL | Open Source Law |
| OSL | Open Source Learning |
| OSL | Open Subscription License |
| OSL | Operating System Loader |
| OSL | Optimization Solutions Library |
| OSL | Osl Setup Lite |