January 29 – Los Angeles Dodgers catcher Roy Campanella suffers a broken neck in an early morning auto accident on Long Island. His spinal column is nearly severed and his legs are permanently paralyzed. Campanella will never play for the Dodgers after their move to Los Angeles, although a newspaper story (showing a picture of him wearing a Brooklyn cap) describes him as being of the Los Angeles Dodgers.
September 21 – The Milwaukee Braves clinch their second consecutive National League pennant with a 6–5 victory over the Cincinnati Reds, thus ensuring a Yankees-Braves World Series for the second straight year.
March 28 – Chuck Klein, 53, slugging right fielder, primarily with the Philadelphia Phillies, who was named the NL's MVP in 1932 and won the Triple Crown one year later; the 7th player to hit 300 home runs, winning four league titles
April 14 – John Freeman, 57, outfielder for the 1927 Boston Red Sox
June 9 – John Fick, 37, pitcher for the 1944 Philadelphia Blue Jays
August 1 – Ike Boone, 61, an outfielder for the New York Giants, Boston Red Sox, Chicago White Sox, and Brooklyn Dodgers between 1922 and 1932, who posted an ML career average of .321, compiled a .370 BA for the highest minor league all-time, and set a professional baseball record in 1929 collecting 553 total bases while playing in the Pacific Coast League
November 21 – Mel Ott, 49, Hall of Fame outfielder and 12-time All-Star for the New York Giants who held National League career record for home runs (511), leading league 6 times
December 8 – Tris Speaker, 70, Hall of Fame center fielder known for spectacular defense as well as superlative batting, becoming the second player to compile over 3,500 hits and posting a .345 career average