1920–21 NCAA men's basketball season

The 1920–21 NCAA men's basketball season began in December 1920, progressed through the regular season and conference tournaments, and concluded in March 1921.

Rule changes

 * The basket was moved to 2 ft from the baseline and the padded wall behind the basket was ruled out of bounds. Previously, players could climb the wall to get closer to the basket for a shot.
 * A new substitution rule allowed a player who left the game to re-enter it once. Previously, a player who left the game could not re-enter it.

Season headlines

 * The Southern Intercollegiate Athletic Conference played the first college conference championship tournament. Kentucky won.
 * In February 1943, the Helms Athletic Foundation retroactively selected Penn as its national champion for the 1920–21 season.
 * In 1995, the Premo-Porretta Power Poll retroactively selected Missouri as its national champion for the 1920–21 season.

Conference winners and tournaments
NOTE: The Southern Intercollegiate Athletic Association did not have an official regular-season champion, but it sponsored the 1921 Southern Intercollegiate Athletic Association men's basketball tournament, whose champion claimed the mythical title of "Champions of the South."

Helms College Basketball All-Americans
The practice of selecting a Consensus All-American Team did not begin until the 1928–29 season. The Helms Athletic Foundation later retroactively selected a list of All-Americans for the 1920–21 season.

Major player of the year awards

 * Helms Player of the Year: George Williams, Missouri (retroactive selection in 1944)

Coaching changes
A number of teams changed coaches during the season and after it ended.