Kenesaw Mountain Landis was an American jurist who served as a United States federal judge from 1905 to 1922 and the first Commissioner of Baseball from 1920 until his death. He is remembered for his resolution of the Black Sox Scandal, in which he expelled eight members of the Chicago White Sox from organized baseball for conspiring to lose the 1919 World Series and repeatedly refused their reinstatement requests. His iron rule over baseball in the near quarter-century of his commissionership is generally credited with restoring public confidence in the game.

The Commissioner of Baseball is the chief executive officer of Major League Baseball (MLB) and the associated Minor League Baseball (MiLB) – a constellation of leagues and clubs known as "organized baseball". Under the direction of the Commissioner, the Office of the Commissioner of Baseball hires and maintains the sport's umpiring crews, and negotiates marketing, labor, and television contracts. The commissioner is chosen by a vote of the owners of the teams. The incumbent MLB commissioner is Rob Manfred, who assumed office on January 25, 2015.