OTL may stand for:
- On the Level, album by Status Quo
- Out to Lunch (disambiguation)
- One True Love, Philippine film
- Optical channel Transport Lane, multi-lane interface for the Optical Transport Network (OTN)
- Oradea Transport Local
- Over-the-line, a variant of softball played mostly in Southern California
- Over Time Limit
- Output transformerless, a vacuum tube amplifier topology
- Outside the Lines, an American sports television series focusing on off-the-field stories
- On the lam
- In alternate history fiction, "OTL" stands for "Our Timeline" or "Original Timeline"
- Oracle Template Library
- A posture emoticon, denoting failure; it resembles a man bowing. 'O' is a head, 'T' is upper body with arms, 'L' is legs.
- Overtime loss (ice hockey)
- Outside the Lines, an American television program on ESPN
- Output transformerless, an audio amplifier output stage coupling method.