| Acronym | Definition |
|---|
| OTL | On the Low |
| OTL | Opportunity to Learn (various organizations) |
| OTL | Outside the Lines |
| OTL | Oracle Time and Labor (business software) |
| OTL | Online Teaching and Learning |
| OTL | Operations Team Leader |
| OTL | Overtime Loss (hockey) |
| OTL | Oracle Time and Labor |
| OTL | Open Type Layout |
| OTL | Oracle Top Link |
| OTL | Outline |
| OTL | Output Transformer Less |
| OTL | Over The Line (tournament in San Diego, CA, USA) |
| OTL | Out To Lunch |
| OTL | Office of Technology Licensing |
| OTL | One True Love (Internet slang) |
| OTL | Overhead Transmission Line |
| OTL | Off the Line (marching band) |
| OTL | Off the List |
| OTL | Output Transformer-Less (audio systems) |
| OTL | Oberstleutnant (German military; Lieutenant Colonel) |
| OTL | Our Timeline |
| OTL | On the Loose (outdoors club of the Claremont Colleges) |
| OTL | OpenType Layout |
| OTL | Onward Technologies, Ltd. (various locations) |
| OTL | Only the Lonely |
| OTL | Over Time Limit (auto racing) |
| OTL | Orange Township Library (Rome City, IN) |
| OTL | Operational Test Launch |
| OTL | Outer Tube Limit (heat exchangers) |
| OTL | Optical Transmission Loss |
| OTL | Observer Target Line |
| OTL | Oxidizer Topping Line |
| OTL | Outdoor Test Laboratory |
| OTL | Ogden Technology Laboratories |
| OTL | Oil Tank Light |
| OTL | Optical Transport Layer (Ciena) |
| OTL | Operating Time Limit (aviation) |
| OTL | Operating Temperature Limit |
| OTL | Optimum Transmission Level |
| OTL | Oldtimer Tractorenclub Lochristi (Dutch: Lochristi Oldtimer Tractor Club; Lochristi, Belgium) |