AC, A.C. or Ac may refer to:
AC/DC are an Australian rock band, formed in Sydney in 1973 by brothers Malcolm and Angus Young. A hard rock/blues rock band, their music has also been called heavy metal, although they refer to themselves as "a rock and roll band, nothing more, nothing less".
The Achaemenid Empire ( c. 550–330 BC), also called the First Persian Empire, was an empire based in Western Asia, founded by Cyrus the Great.
The Academy Award for Best Picture is one of the Academy Awards presented annually since the awards debuted in 1929, by the Academy of Motion Picture Arts and Sciences (AMPAS).
An actor (often actress for females; see terminology) is a person who portrays a character in a performance.
Academi is an American private military company founded in 1997 by former Navy SEAL officer Erik Prince as Blackwater, renamed as Xe Services in 2009 and now known as Academi since 2011 after the company was acquired by a group of private investors.
An acronym is a word or name formed as an abbreviation from the initial components in a phrase or a word, usually individual letters (as in NATO or laser) and sometimes syllables (as in Benelux).
Acetic acid , systematically named ethanoic acid , is a colourless liquid organic compound with the chemical formula CH3COOH (also written as CH3CO2H or C2H4O2).