ADN is a three-letter acronym that may refer to:
In Technology:
- Adobe Digital Negative (file format), a raw image format designed by Adobe Systems
- Application Delivery Network, a suite of technologies for improved delivery of applications across the Internet
- Autodesk Developer Network, a program for developers working with Autodesk software
- Aircraft Data Network, a proposed specification for data networking standards for commercial aircraft installations
- Advanced Digital Network, a leased 56k digital phone line used commonly with mainframe terminal multiplexers
- ADN - Abbreviated Dialing Numbers: SIM file - Telephone numbers stored in the SIM memory
In Sciences:
- Auditory Disability with Normal hearing, a term for King-Kopetzky syndrome
- Ammonium dinitramide, a rocket propellant
- DNA
In Politics:
- Acción Democrática Nacionalista (Nationalist Democratic Action), a political party of Bolivia
- Alleanza Democratica Nazionale (National Democratic Alliance (Italy)), a former political party of Italy
In Media:
- Allgemeiner Deutscher Nachrichtendienst, the state news agency of East Germany
- Anchorage Daily News, an Alaskan newspaper
- ADN (newspaper), a Spanish free daily newspaper
In Education:
- Associate Degree in Nursing, similar to Associate of Science in Nursing
- Assistant Director of Nursing
In other uses:
- Abbreviated dialing number
- ADN, IATA airport code for Andes Airport in Andes, Antioquia, Colombia
- ADN, National Rail code for Ardrossan Town railway station, United Kingdom
- "Any Day Now", as abbreviated in text messaging
- Ashley, Drew and Northern Railway, a defunct railroad in Arkansas