Basketball was introduced in the Olympic Games in 1936. The international game is regulated by the Fédération Internationale de Basketball Amateur, and championship tournaments are held periodically. The amateur game played in the United States is regulated by the Amateur Basketball Association of the USA. Championship play-offs take place at the end of each college basketball season (December through March) among the many nationwide intercollegiate conferences. Two important postseason tournaments are also held, the National Invitation Tournament (NIT; begun in 1938) and the National Collegiate Athletic Association (NCAA) tournaments for men (begun in 1939) and women (begun in 1982), which determine the NCAA champions.

High school basketball for girls and boys, one of the most popular spectator sports, attracts large crowds throughout the United States. Statewide tournaments determine the championship teams. Other forms of amateur competition include variations of the game for younger children and for people with disabilities.