UAC may refer to:
Computing
- User Account Control, a security feature in Microsoft Windows
- Session Initiation Protocol#User agent client
Organizations
- Ulster Army Council, 1973 Northern Ireland loyalist paramilitary group
- Undeb Amaethwyr Cymru, the Farmer's Union of Wales
- Unemployment Action Center, a non-profit organization in New York City, US
- United Apostolic Church
- Union of Catholic Apostolate
- Université d’Abomey-Calavi, part of the National University of Benin
- United Africa Company, 20th-century British company
- United Africa Company of Nigeria, formerly a subsidiary of United Africa Company
- United Aircraft Corporation, Russian aerospace and defense company
- United Arab Command, of the Arab League
- United Athletic Conference (football), an American college football conference that started play in 2023.
- Western Athletic Conference, the NCAA Division I conference scheduled to rebrand as the United Athletic Conference in 2026
- Universidad Andina del Cusco, Peru
- Universities Admissions Centre, Australia
- Urban Appalachian Council, Cincinnati, US
Other
- Unaccompanied Alien Children, United States government classification for children in immigration custody
- Unified Arab Code, a Civil Code produced by the Arab League between 1988 and 1996
- Urban adult contemporary, radio music format
- Union Aerospace Corporation, fictional military contractor in the Doom video game franchise
- UAC, a codon for the amino acid tyrosine