January 28 – 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.
February 6 – Ted Williams signs a one-year contract with the Boston Red Sox. Reports on the worth of the contract estimate from $135,000 to $150,000. Either way, Williams becomes the highest paid player in major league history.
April 15 – In the first Major League Baseball game played on the West Coast, Rubén Gómez of the San Francisco Giants hurls an 8-0 shutout against the Los Angeles Dodgers. Giants' shortstop Daryl Spencer hits the first Major League home run on the Pacific Coast. A park-record 23,192 fans pack Seals Stadium to witness the historic game.
September 14 – The New York Yankees sweep a doubleheader against the Kansas City Athletics, 5-3 and 12-7 (14 innings), clinching their fourth straight American Leaguepennant.
September 20 – At Memorial Stadium, Hoyt Wilhelm of the Baltimore Orioles no-hits the New York Yankees 1-0, striking out eight along the way. It is the first no-hitter since the franchise's move to Baltimore. Wilhelm had pitched exclusively in relief prior to this season; this was only his ninth career start.
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.
The American League announces that its Opening Day will be April 9 making it earliest date ever to open the junior circuit's regular season.
The Boston Red Sox sign teenage sensation Carl Yastrzemski to a reported bonus of $100,000. The future Hall of Famer will make his major league debut with Boston in the 1961 season.
November 30 – Italian baseball commissioner Prince Borghese visits the United States to seek aid in organizing Italian teams.
International League President Frank Shaughnessy reports that club owners are sympathetic to player demands for a pension plan, but says there is no way that $250,000 can be raised to start one.
National League President Warren Giles says he doubts New York City will get a franchise for several years. He says the NL will reject expansion now, even if assured of a stadium and financial backing.
December 4 – The American Association expands to 10 teams by admitting the Houston Buffs, Dallas Rangers, and Fort Worth Cats from the Texas League. This effectively denudes the Texas League, leaving it with five teams and a vacancy.
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
April 20 – Chet Nourse, 70, pitcher for the 1909 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
September 6 – Tommy de la Cruz, 46, Cuban pitcher for the 1944 Cincinnati Reds, and one of many players who only appeared in the majors during World War II
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