ATL
- AT-L
- AT1 (disambiguation)
- ATI (disambiguation)
- ATL (band)
- ATL (company)
- ATL (film)
- ATLAS Transformation Language
- ATLS (disambiguation)
- Above the Law (group)
- Above the line (disambiguation)
- Across the Line (radio show)
- Active Template Library
- Adult T-cell leukemia
- Advanced Tactical Laser
- Air Atlantic
- All Time Low
- Alternating-time Temporal Logic
- Americans for Technology Leadership
- Among the Living
- Anti-Terrorism Act of 2020
- Association of Teachers and Lecturers
- Atlanta
- Atlanta Braves
- Atlanta Falcons
- Atlanta Hawks
- Atlanta United FC
- Atlantic
- Atlantis
- Atlas
- Atlatl
- Attleborough railway station
- Azienda Trasporti Livornese
- Dr. Atl
- Hartsfield–Jackson Atlanta International Airport
- List of United States Navy amphibious warfare ships
- Livorno
- Metropolitan Atlanta Rapid Transit Authority
- Peachtree station
- Robin ATL
- TL (disambiguation)