MLB permanently retired Jackie Robinson’s number 42 in 1997. The league-wide retirement took place on April 15, 1997, exactly 50 years after Robinson made his Brooklyn Dodgers debut and broke Major League Baseball’s modern color barrier.
The decision was unusual because uniform numbers are normally retired by individual clubs. MLB Commissioner Bud Selig announced that no future player could be issued number 42 by any major-league team. The Dodgers had already retired Robinson’s number in 1972, shortly before his death, but the 1997 action honored him across the entire sport.
A grandfather rule allowed players already wearing number 42 to keep it. New York Yankees closer Mariano Rivera became the last regular MLB player to wear it, retiring after the 2013 season. Since 2004, players and coaches have also worn 42 each April 15 for Jackie Robinson Day, making the number a continuing symbol of baseball integration and Robinson’s civil-rights legacy.