AC or Ac may refer to:

  • Air conditioner, a machine that produces cool air
  • Air conditioning, the mechanical process of cooling air in enclosed spaces
  • Anarcho-capitalism, a form of free-market anarchism
  • Ante Christum or A.C., a Latin term meaning "before Christ"
  • Anthrocon, the largest furry convention in the world held in Pittsburgh, Pennsylvania
  • Assessment center, a process to evaluate candidates for a job
  • Average cost, in economics
  • Acre, a unit of area with the symbol ac

Read more about AC:  Science, Places, Computing, Job Titles / Ranks, Entertainment, Organizations, Law