K4 or K-4 may refer to:

Military

  • Daewoo K4, a South Korean automatic grenade launcher
  • HMS K4, a 1915 British K class submarine
  • K 4 or Norrland Dragoon Regiment, a Swedish Army cavalry regiment
  • K-4 (SLBM), an Indian submarine-launched ballistic missile
  • USS K-4 (SS-35), a 1914 United States Navy K-class submarine

Transport

  • China Railway K3/4
  • K-4 (Kansas highway), a highway in Kansas
  • Kalitta Air, IATA code K4, an American cargo airline
  • LNER Class K4, a British class of 2-6-0 steam locomotives
  • London Buses route K4, a Transport for London contracted bus route
  • PRR K4s or Pennsylvania Railroad Type K4, a class of American 4-6-2 steam locomotives
  • Kia K4 (2025), a compact car successor to a Kia Forte
  • Kia K4 (China), a Chinese compact car by Dongfeng Yueda Kia

Other uses

  • K4, a four-man sprint kayak
  • K4, a model of the British red telephone box
  • K4, a normal modal logic
  • K, in graph theory, the complete graph of four vertices
  • K, in abstract algebra, the Klein four-group
  • K4 (mountain) or Gasherbrum II, a mountain between China and Pakistan
  • Kawai K4, a digital synthesizer
  • Koalisyon ng Katapatan at Karanasan sa Kinabukasan (K4, Coalition of Truth and Experience for Tomorrow), a Philippine political coalition
  • K4, an inscription on the sculpture Kryptos

See also

  • KKKK (disambiguation)