DACS may refer to:
- Digital Access Carrier System, telecommunications equipment in the United Kingdom
- Digital Access and Cross-connect System, telecommunications equipment in the United States
- Data & Analysis Center for Software, United States Department of Defense information analysis center
- De La Rue Automatic Cash System, early ATM
- Design and Artists Copyright Society, UK copyright collecting society for visual art
- Describing Archives: A Content Standard, standard for describing collections
- Distributed Access Control System, single sign-on and role-based access control system
- Danger Area Crossing Service (aviation)