K3

K3 may refer to:

Transportation

 * China Railway K3/4
 * K-3 (Kansas highway), a state highway in Kansas
 * London Bus route K3
 * Taquan Air, an Alaskan commuter airline (by IATA code)
 * K-3 cart
 * Kia Forte, a compact car sold as Kia K3 in South Korea
 * Kia K3 (BL7), a subcompact car
 * LNER Class K3, a class of British steam locomotives
 * GSWRI Class K3, a Great Southern and Western Railway (Ireland) steam locomotive

Military

 * Units
 * Life Regiment Hussars, Swedish cavalry regiment
 * Weapons
 * K-3 (rifle), an Armenian-made bullpup rifle
 * Daewoo K3, a light machine gun
 * Ships
 * Soviet submarine K-3 Leninsky Komsomol, the first Soviet nuclear submarine
 * USS K-3 (SS-34), a 1914 United States Navy K-class submarine
 * HMS K3, a 1916 British K-class submarine
 * HMS Heliotrope (K03), a 1940 Royal Navy Flower-class corvette
 * Airfields
 * Pohang Airport, by United States Air Force designator during the Korean War

Science, technology, computing and mathematics

 * The Kleene logic K3
 * A version of the K (programming language)
 * K3 surface, a compact complex surface in mathematics
 * Menadione, vitamin K3
 * K3, 1774 marine chronometer made by Larcum Kendall
 * Pentax K-3, a digital SLR camera

Media and entertainment

 * K3 (band), a Belgian/Dutch girl group
 * K3 (television), a Catalan television channel
 * K3: Prison of Hell, a 2009 pornographic horror film
 * K3, a world in Donkey Kong Country 3: Dixie Kong's Double Trouble!

Other uses

 * K3 League, a South Korean football league
 * Gasherbrum IV, a mountain in the Karakoram previously surveyed as K3. Sometimes erroneously recorded as Broad Peak.
 * Kankakee, Illinois, an expression or abbreviation used to identify Kankakee, IL