ACK or Ack may refer to:
Arts and entertainment
edit- Amar Chitra Katha, an Indian comic book series
Technology
edit- Acknowledgement (data networks)
- ACK (TCP), the control character used in the Transmission Control Protocol to acknowledge receipt of a packet
- Amsterdam Compiler Kit, a retargetable compiler suite and toolchain
Transportation
edit- Acklington railway station (Station code: ACK), a rail station in the UK
- Armstrong Whitworth F.K.8, an early aircraft known as the "Big Ack"
- Nantucket Airlines or ACK Air, an American airline
- Nantucket Memorial Airport (IATA: ACK, FAA LID: ACK), an airport in the US
Other uses
edit- Assumption College, Kilmore, an Australian school
- Aka-Kora language (ISO 639-3: ack), an extinct Great Andamanese language
- TNK2 or ACK or ACK1, an enzyme that in humans is encoded by the TNK2 gene