January 12 - Boston Red Sox star Ted Williams receives his discharge from the U.S. Marine Air Corps after a three-year stint serving in World War II. In spite of the long absence from competitive baseball, Williams will return to the major leagues by hitting .342 with 38 home runs and 123 RBI in 1946.
January 12 - The first official professional game is played in Venezuela, launching the newly constituted four-team Liga de Béisbol Profesional de Venezuela. The league is composed of four teams: Cervecería Caracas, Magallanes, Vargas and Venezuela. The inaugural game is won by Magallanes over Venezuela, 5–2, behind strong pitching from Alex Carrasquel, who gives up 11 hits in a complete game effort.
January 20 - In a classic pitching matchup played in Caracas, Venezuela, Alex Carrasquel of Magallanes beat Roy Welmaker and Vargas club, 3–2, in 17 innings. In the six-and-a-half-hour marathon, Carrasquel is good enough to silence the bats of Roy Campanella and Sam Jethroe. Both pitchers go the distance in one of the greatest matchups ever.
February 19 - New York Giants OF Danny Gardella becomes the first major leaguer to announce he is jumping to the "outlaw" Mexican League, the first shot in the series of events that will dominate baseball even more than the return of all the war veterans. His attempt to return to Major League Baseball a few years later will initiate a major court battle.
July 14 - Player-manager Lou Boudreau of the Cleveland Indians hits four doubles and one home run, but Ted Williams wallops three homers and drives in eight runs, as the Boston Red Sox top the Indians, 11–10. In the Sox second-game win, the famous Boudreau Shift is born. Boudreau shifts all his players, except the third baseman and left fielder, to the right side of the diamond in an effort to stop Williams. Ted grounds out and walks twice while ignoring the shift.
August 9 - All games (four each for both the American and National Leagues) were played at night for the first time in Major League history.
March 28 - Cumberland Posey, 55, owner of the Negro Leagues' Homestead Grays since the 1920 who built the team into a perennial power; previously an outfielder and manager
April 4 - Harry Cross, 64, sportswriter for several New York newspapers since 1909
April 5 - Wally Rehg, 57, right fielder for the Boston Red Sox, Boston Braves and Cincinnati Reds between 1912 and 1919, later a minor league player and manager from 1910 to 1930
May 19 - John K. Tener, 82, president of the National League from 1913 to 1918; won 25 games as pitcher from 1888-1890
May 30 - Billy Earle, 78, catcher for five seasons, and five teams from 1889 to 1894.
June 17 - James Isaminger, 65, sportswriter for Philadelphia newspapers from 1905 to 1940 who played a major role in breaking the story of the Black Sox scandal
August 6 - Tony Lazzeri, 42, All-Star second baseman for the New York Yankees who batted .300 five times and had seven 100-RBI seasons; had two grand slams and 11 RBI in a 1936 game, and batted .400 in 1937 World Series
October 4 - John Woods, 48, relief pitcher who played for the 1924 Boston Red Sox
December 10 - Walter Johnson, 59, Hall of Fame pitcher for the Washington Senators who won over 400 games, second only to Cy Young, earned MVP awards in 1913 and 1924, and recorded 3508 strikeouts and 110 shutouts, both easily records; posted career 2.17 ERA and won 20 games 12 times, including 30-win seasons in 1912-13; led AL in strikeouts twelve times, ERA five times; won 38 1-0 games, also losing 26 by same score
December 10 - Walter Moser, 65, pitcher for the Philadelphia Athletics, Boston Red Sox and St. Louis Browns between 1906 and 1911.
