January 24 – In an effort to speed up the game, Major League Baseball announces a new rule which requires a pitcher to deliver the ball within 20 seconds after taking a pitching position.
February
February 17 – - The Baltimore Orioles obtained pitcher Erv Palica from the Brooklyn Dodgers in exchange for first baseman Frank Kellert and cash considerations. This replaces the previous Preacher Roe deal, which fell through when the Brooklyn pitcher announced his retirement.
April 12 – After a big civic parade, the Athletics open their first season in Kansas City with a win over the Detroit Tigers, 6–2, before a crowd of 32,844.
April 23: The Chicago White Sox tallied a franchise record 29 runs and 29 hits against the host Kansas City Athletics, including seven home runs, in a 29–6 ripping. Sherm Lollar was 5-for-6 with a pair of home runs and five RBI, and became the only player in the decade to get two hits in one inning twice in the same game. Chico Carrasquel hit 5-for-6, and Bob Nieman paced the attack with two homers and seven RBI. Walt Dropo added a homer and seven RBI, while pitcher Jack Harshman and Minnie Miñoso also homered. Carrasquel and Miñoso each scored five runs. Kansas City had homers from Vic Power and Bill Renna. Bobby Shantz was the losing pitcher.
June 1 – Duke Snider hit three home runs at Ebbets Field, helping the Brooklyn Dodgers to an 11–8 victory over the Milwaukee Braves. Pee Wee Reese, Jackie Robinson and Roy Campanella also belted solo homers for the Dodgers, to set a franchise record with six home runs in a single game.
July
July 12 – In the All-Star Game in Milwaukee's County Stadium, the American League takes a five run lead on a three-run home run by Mickey Mantle off Robin Roberts, only to see the National League tie it. Milwaukee Braves pitcher Gene Conley strikes out the side in the 12th inning, and Stan Musial of the St. Louis Cardinals homers off Boston Red Sox pitcher Frank Sullivan to seal a 6–5 victory.
July 26 - In a key nighttime game at Yankee Stadium, the New York Yankees beat the Chicago White Sox 1-0. The game's only run occurred in the bottom of the 6th inning when Yogi Berra hit his 17th homer of the season off the White Sox' Dick Donovan. Tommy Byrne was the winning pitcher as he held the White Sox to just 4 hits, all of them singles.
July 31 – On the first anniversary of his four-home run game, Milwaukee Braves first baseman Joe Adcock has his arm broken by a pitch from the New York Giants' Jim Hearn. Adcock will miss the rest of the season.
August
August 20 – The Chicago White Sox rally to edge the Detroit Tigers‚ 8–7. Nellie Fox and Jim Rivera pace the attack with four hits apiece‚ while Chico Carrasquel adds a home run. George Kelldrives in five runs for the White Sox. The win leaves Chicago tied in second place with Cleveland ‚ and a game in back of New York.
September
September 8 – The Brooklyn Dodgers clinch the National League pennant by beating the Milwaukee Braves, 10–2, for their 8th NL title. The Dodgers also break their own Major League Baseball record for the earliest clinching, set in.
September 16 – The Kansas City Athletics score seven runs in the first inning and roll to a 13–7 win over the faltering Chicago White Sox. The third place Sox lose their 10th in 17 games. Héctor López hits a three-run home run in the first to start the scoring and later in the game Joe Astroth adds another three-run homer. George Kell and Chico Carrasquel hits solo homers for Chicago. In the 8th inning, 16-year-old shortstop Alex George debuts for Kansas City‚handling two chances in the field flawlessly and making out in his one at bat. George will go 1-for-10 in this his only Major League season.
October 4 – No more "wait till' next year" as the Brooklyn Dodgers, behind the pitching of Johnny Podres, brings its first, and only, World Championship to Brooklyn after seven previous frustrated World Series appearances in a 2-0 win over the New York Yankees. The Dodgers win the Series four game to three, and Podres is named Most Valuable Player – the first time the award is given in the World Series.
October 25 – Chicago White Sox GMFrank Lane trade SS Chico Carrasquel and CFJim Busby to the Cleveland Indians in exchange for CF Larry Doby. The trade was made by Lane to make room for Carrasquel's fellow Venezuelan and future Hall of FamerLuis Aparicio.
November
November 2 – The Pittsburgh Pirates name Bobby Bragan as their new field manager, replacing Fred Haney.
November 12 – Fred Hutchinson replaces Harry Walker as the St. Louis Cardinals manager. With the departure of Walker, next season will be the first time in National League history without a player-manager.
December 8 – Lenny Yochim of the Leones del Caracas became the first pitcher to throw a no-hitter in the Venezuelan Professional Baseball League. The 27-year-old left-hander accomplished the feat in a 3–0 victory over the Navegantes del Magallanes helped by catcher Earl Battey. Ramón Monzant was credited with the loss. Previously, the screwballer Yochim had pitched for the Pittsburgh Pirates in part of two seasons.
January 13 – Bill Dinneen, 78, pitching star of the 1903 World Series, while winning three games for the champion Boston Americans against the Pittsburgh Pirates, including the first two shutouts in World Series history.
June 2 – Harry Eccles, 61, pitcher who played for the Philadelphia Athletics during the 1915 season.
June 6 – Mike Kelley, 79, first baseman for the 1899 Louisville Colonels, later became a long time minor league baseball owner and manager.
June 16 – Mike Morrison, 88, pitcher who played for the Cleveland Spiders, Syracuse Stars and Baltimore Orioles in part of three seasons between 1887 and 1890.
June 18 – Jack Katoll, 82, German pitcher who played for the Chicago Orphans, Chicago White Sox and Baltimore Orioles in a span of four seasons from 1898–1902.
June 22 – Frankie Hayes, 40, highly regarded defensive catcher and a five-time All-Star while playing for the Philadelphia Athletics, St. Louis Browns, Cleveland Indians, Chicago White Sox and Boston Red Sox, who led the American League three times in total chances per game, twice each in fielding average, putouts, double plays and errors, and once in assists. Besides, his 29 double plays in 1945 is the second-highest total ever for a catcher. Additionally, he caught 312 consecutive games between October 1943 and April 1946, a Major League record, and was durable enough to catch all 155 Athletics games in 1945, as he set a still-standing American League season record.
June 27 – Harry Agganis, 26, Boston Red Sox first baseman and former Boston University football star, who compiled outstanding records as a quarterback in his student heyday, becoming the first person in BU history to receive All-American honors.
June 29 – Horace Milan, 61, outfielder who played with the Washington Senators in the 191 and 1917 seasons.
October 4 – Stan Baumgartner, 60, relief pitcher who spent eight seasons in the majors with the Philadelphia Phillies and Philadelphia Athletics between 1914 and 1926.
October 5 – Lyman Lamb, 60, third baseman for the St. Louis Browns during two seasons from 1920–1921.
October 9 – Howie Fox, 34, pitcher for the Cincinnati Reds, Philadelphia Phillies and Baltimore Orioles from 1944 to 1954.
October 9 – Jim Jackson, 77, utility outfielder who played for the Baltimore Orioles, New York Giants and Cleveland Naps over four seasons from 1901–1906.
October 13 – Fred Lear, 61, third baseman who played for the Philadelphia Athletics, Chicago Cubs and New York Giants in part of four seasons between 1915 and 1920.
October 18 – George Murray, 57, who pitched from 1922 to 1933 for the New York Yankees, Boston Red Sox, Washington Senators and Chicago White Sox.
October 26 – Jack Bushelman, 70, pitcher who played with the Cincinnati Reds in the 1909 season and for the Boston Red Sox from 1911 to 1912.
October 27 – Clark Griffith, 85, Hall of Fame pitcher and manager, and owner of the Washington Senators since 1920.
November
November 3 – John Merritt, 61, backup outfielder who appeared in just one game with the New York Giants in the 1913 season.
November 4 – Cy Young, 88, Hall of Fame pitcher who won a record 511 games over a 22-year career with five clubs from 1890 to 1911, being a 30-game winner five seasons, a 20-game victor sixteen times, pitching a perfect game, two no-hitters, and while being a member of the 1903 Boston Americans hurling the first pitch in a World Series game.
November 5 – Frank Gregory, 67, pitcher for the Cincinnati Reds in their 1912 season.
November 12 – Sam Crane, 61, shortstop who played for the Philadelphia Athletics, Washington Senators, Cincinnati Reds and Brooklyn Robins in part of seven seasons spanning 1914–1922.
November 19 – Otto Jacobs, 66, catcher for the 1918 Chicago White Sox.
November 22 – Danny Murphy, 51, catcher who played briefly for the New York Giants in the 1892 season.
November 23 – Fred Tauby, 49, part-time outfielder who played with the Chicago White Sox in the 1935 season and for the Philadelphia Phillies in 1937.
November 30 – John Stone, 50, outfielder for the Detroit Tigers and Washington Senators from 1928 to 1938, who hit over.300 in seven of his eleven seasons, with a career-high.341 in 1936.
December
December 6 – Honus Wagner, 81, legendary Hall of Fame shortstop of the Pittsburgh Pirates who won eight National League batting crowns and led the league in runs batted in, stolen bases, doubles and slugging average at least five times each in a 21-year career, posting an overall batting line of.328/.391/.467, having scored 1,739 runs, connect 3,420 hits and stolen 723 bases.
December 8 – Buck Washer, 73, pitcher for the Philadelphia Phillies during the 1905 season.
December 9 – Curt Walker, 59, right fielder who played twelve seasons from 1919–1930 for the Philadelphia Phillies, New York Yankees, Cincinnati Reds and New York Giants, compiling a slash line of.304/.374/.440 and 1,475 hits in 1,359 games, while batting a.300 or better average in seven seasons.
December 17 – Rube DeGroff, 76, backup outfielder for the St. Louis Cardinals during two seasons from 1905 to 1906.
December 18 – George Caster, pitcher who played for the Philadelphia Athletics, St. Louis Browns and Detroit Tigers during twelve seasons from 1934–1946, as well as a member of the 1945 World Champion Tigers.
December 18 – Francisco José Cróquer, 35, Venezuelan sportscaster specialized in baseball and boxing, who achieved international renown and became a household name in Latino communities after joining the Gillette Cavalcade of Sports in the late 1940s.
December 19 – Moxie Divis, 61, outfielder who played for the Philadelphia Athletics during the 1916 season.
December 23 – Joe McManus, 68, who pitched in 1913 for the Cincinnati Reds.
December 24 – Jake Boultes, 71, who played from 1907 through 1909 for the Boston Doves, mostly as a pitcher, although he also played a handful of games as a shortstop and third baseman.
December 27 – Lord Byron, 83, National League umpire from 1913 to 1919, while officiating 1,012 games and the 1914 World Series.
December 27 – Jim Fairbank, 74, pitcher who played for the Philadelphia Athletics during the 1903 and 1904 seasons.
December 31 – Clint Brown, 52, relief pitcher for the Cleveland Indians and Chicago White Sox in a span of fifteen seasons from 1928–1942, who posted a career 89-93 W-L record with 64 saves and 4.26 ERA, leading the American League relievers in 1939 in appearances, games finished, saves and innings, ending 11th in the voting for the American League MVP Award.
