K4

K4 or K-4 may mean:
* K-4 (Kansas highway), a highway in Kansas
* K4 (programming language), the fourth version of the k programming language created by Arthur Whitney
* Daewoo K4, a 40 mm highspeed Automatic Grenade Launcher by use in the South Korean Army
* GSWRI Class K4, a Great Southern and Western Railway Irish steam locomotive
* HMS K4, a 1915 British K class submarine
* LNER Class K4, a British class of 2-6-0 steam locomotives
* London Buses route K4, a Transport for London contracted bus route
* SoftCare K4, a paperless editorial system, used in tandem with Adobe InCopy (used by newspapers, magazines and book publishers)
* USS K-4 (SS-35), a 1914 United States Navy K-class submarine

and also :
* K4, a Slovenian discotheque
* K4, an abbreviation for a four-man Sprint Kayak
* Koalisyon ng Katapatan at Karanasan sa Kinabukasan, a Philippine Political Coalition
* Gasherbrum II mountain
* K4, a model of the iconic British red telephone box
* the normal modal logic Kripke semantics#Correspondence and completeness
* Kalitta Air IATA code
* Dilaudid, slang term for the narcotic analgesic
* Pre-Kindergarten education

K 4, a Swedish regimental designation (4th Cavalry Regiment) that has been used by the following units:
* Smålands husarregemente (1816–1927)
* Norrlands dragonregemente (1928–)