ADL
- ADL astronomical society
- ADL/ADC class diesel multiple unit
- ADLS (disambiguation)
- ALD (disambiguation)
- Action description language
- Activities of daily living
- Adelaide
- Adelaide Airport
- Adl
- Adlington (Lancashire) railway station
- Advanced Distributed Learning
- Advance–decline line
- Akademiska Damkören Lyran
- Alder Lake
- Aleppo Defenders Legion
- Alexander Dennis
- Amalgamated Dairies Limited
- Animal Defense League
- Anti-Defamation League
- Architecture description language
- Arena Developmental League
- Argument-dependent name lookup
- Armenian Democratic Liberal Party
- Arthur D. Little
- Assertion definition language
- Aurelio De Laurentiis
- Gallong language
- On-Line Systems