Judo (柔道, jūdō^?, meaning "gentle way") is a modern martial art, combat sport and Olympic sport created in Japan in 1882 by Jigoro Kano. Its most prominent feature is its competitive element, where the object is to either throw or takedown one's opponent to the ground, immobilize or otherwise subdue one's opponent with a grappling maneuver, or force an opponent to submit by joint locking or by executing a strangle hold or choke. Strikes and thrusts by hands and feet as well as weapons defences are a part of judo, but only in pre-arranged forms (kata) and are not allowed in judo competition or free practice (randori).

The philosophy and subsequent pedagogy developed for judo became the model for other modern Japanese martial arts that developed from koryū (古流^?, traditional schools). The worldwide spread of judo has led to the development of a number of offshoots such as Sambo and Brazilian Jiu-Jitsu. Judo practitioners are called judoka.

The early history of judo is inseparable from its founder, Japanese polymath and educator Jigoro Kano (嘉納 治五郎, Kanō Jigorō^?, 1860–1938), born Shinnosuke Kano (嘉納 新之助, Kanō Shinnosuke^?). Kano was born into a relatively affluent family. His father, Jirosaku, was the second son of the head priest of the Shinto Hiyoshi shrine in Shiga Prefecture. He married Sadako Kano, daughter of the owner of Kiku-Masamune sake brewing company and was adopted by the family, changing his name to Kano, and ultimately became an official in the Bakufu government.