KD
KD and variants may refer to:

Businesses and organizations
KD Avia, a former Russian airline (IATA code KD)
KD Transportation Group, a South Korean bus company
Kalstar Aviation (IATA code KD)
Kappa Delta, a National Panhellenic sorority
Kendell Airlines, a former Australian airline (IATA code KD)
Keolis Downer, an Australian public transport operator
Kings Dominion, an amusement park located in Doswell, Virginia
Koleje Dolnośląskie, a Polish rail operator
Köln-Düsseldorfer, a river cruise operator based in Cologne, Germany

Science and technology
Dissociation constant (KD), a type of equilibrium constant
K-d tree, a data structure in computing
Kawasaki disease, an inflammatory disease causing vasculitis and sometimes aneurysm
Kienböck's disease, an avascular necrosis in the lunate bone of the wrist
Toyota KD Engine, a engine manufactured by Toyota
Gene knockdown, a genetic modification technique

Other uses
K.D., a 2019 Tamil film
KD Station, a meat packing plant, later business and entertainment complex, in Sioux City, Iowa, US
Kapal DiRaja, a ship prefix used in the Royal Malaysian Navy
Katamari Damacy, a PlayStation 2 video game
Kentucky Deluxe, a brand of American whiskey
k.d. lang, a Canadian pop singer-songwriter
Kevin Durant, a professional basketball player
Krisdayanti, an Indonesian singer and actress
K?d, an American DJ and record producer
Christian Democrats (Sweden), a Swedish political party
Christian Democrats (Finland), a Finnish political party
Khaki drill, a fabric used in 20th-century British military uniforms
Knock-down kit, a kit of part to assemble something
Kraft Dinner, a convenience food product
Kuwaiti dinar, a currency, sometimes represented "K.D." (ISO code KWD)
Kill-death ratio, a statistic in player-versus-player combat multiplayer video games

See also
K-Dee, American rapper
Kadee, model railroad company
Kaydee, pop band
Kaydee (disambiguation)