WAC is the code for Warrington Central railway station; or, as a three-letter acronym, may refer to:
- WAC Lighting Company
- WAC Corporal, the first U.S. sounding rocket
- Walker Art Center, a modern art museum in Minneapolis, Minnesota, USA
- Walton Arts Center, a performing arts center in Fayetteville, Arkansas, USA, near the University of Arkansas.
- Wan Chai Station, Hong Kong; MTR station code WAC
- Warner Archive Collection
- Washington Administrative Code, code of administrative regulations of Washington, USA
- Washington College of Chestertown, Maryland, USA
- Waste Acceptance Criteria, European criteria required to establish whether a waste is suitable for landfill
- We are Church, a reformist organization within the Roman Catholic Church
- Weighted average cost of capital, a term used in inventory management and accounting
- Western Athletic Conference, an American college athletics league
- Wholesale Applications Community, community of mobile phone developers
- Wydad Casablanca or Widad Athletic Club, a Moroccan sports club
- Wide Awake Club (television), a British children's television series from the 1980s
- Wide Awake Club, a radical wing of the Republican Party in the United States
- Wiener AC, an Austrian sports club
- Women's Army Corps
- Worked All Continents, one of the awards issued by the International Amateur Radio Union
- World Aerobatic Championships
- World aeronautical chart
- World Affairs Council (disambiguation), an American international relations organization
- World Archaeological Congress
- Writing Across the Curriculum, a movement aimed at integrating writing into all academic courses
- World Association of Copepodologists, a non-profit organization promoting research on copepods.