This chapter presents judo as a modern Olympic sport founded in the history and traditions of the Japanese martial arts. It outlines the influences on the founder Jigoro Kanō and the key figures in early development of the Kōdōkan. Judo quickly spread in popularity through students travelling overseas, most notably Yamashita Yoshitsugu, who taught judo to President Theodore Roosevelt, and the role of the Budokwai in London in disseminating judo in Europe. The internationalisation theme continues when Kanō is appointed as a member of the International Olympic Committee, eventually leading to the acceptance of judo onto the Olympic programme in 1964. The establishment of international bodies led to the World Championships, initially for men and later for women; in modern times the World Championships is the premier event on the International Judo Federation World Tour, which sees athletes collect ranking points towards qualification for the Olympic Games. Judo has a culture and tradition of contributing to social good, and efforts supporting displaced persons and peace in the Middle East are explored. Finally, the chapter addresses technical aspects of judo and the role of kata in the teaching of the sport.