Kac
Knight's Armament Company(英語版), an American firearms manufacturer
Kuwait Airways Corporation(英語版), the national airline of Kuwait
KAC Kenitra(英語版), the a Moroccan football club Kenitra Athletic Club
EC KAC(英語版), a professional ice hockey team in the Austrian Erste Bank Hockey League
KAC Masterkey(英語版), a door breaching shotgun system
KAc, abbreviation for potassium acetate(英語版)