AUK may refer to:

• AUK CORP, a Korean semiconductor and optoelectronic manufacturer
• General Claude Auchinleck
• AETN UK, a joint venture of A&E Television Networks and British Sky Broadcasting.
• Auk, a type of bird
• Auk oilfield, oilfield near Aberdeen, Scotland
• The Auk, an American ornithological journal
• AUK, IATA code for Alakanuk Airport in the Kusilvak Census Area, Alaska
• Audax UK, a cycling organisation
• American University in Kosovo, part of the Rochester Institute of Technology
• American University of Kuwait, a non-profit university in Kuwait

An auk is a bird of the family Alcidae in the order Charadriiformes. Extant auks range in size from the least auklet, at 85 g (3 oz) and , to the thick-billed murre, at and . They are good swimmers and divers, but their walking appears clumsy. Modern auks can fly (except for the extinct great auk). Due to their short wings, auks have to flap their wings very quickly in order to fly.