April 19 – Babe Ruth enters Fenway Park as a member of the opposing team for the first time in his career as the Boston Red Sox sweep a doubleheader from Ruth and the New York Yankees. Ruth goes three-for-eight with an RBI.
May 20 – At Griffith Stadium, the Washington Senators and Chicago White Sox go into extra innings tied at three. The ChiSox score two in the fifteenth inning only to be matched by Washington in the bottom of the inning. Chicago then puts up eight runs in the sixteenth to win the game by a final score of 13–5 in sixteen innings. Red Faber pitches all sixteen innings for Chicago.
June 1 – In a slugfest at Dunn Field, the Detroit Tigers defeat the Cleveland Indians 11–10. Detroit's Ty Cobb goes two-for-five with two RBIs and a run scored.
June 24 – Following a 5–3 loss to the Cincinnati Reds, the Philadelphia Phillies fall into last place in the National League. With the Philadelphia A's having been in last place since the 13th, both Philadelphia teams spend the rest of the season in last.
June 28 – The Philadelphia Athletics defeat the Washington Senators 6–2 to end an 18-game losing streak. After giving up two runs on two hits and a walk in the first inning, A's starter Slim Harriss cruises the rest of the way for the complete game victory.
July 1 – Six weeks after recording his 300th, Walter Johnson pitches the only no-hitter of his career, as the Washington Senators top the Boston Red Sox, 1–0.
July 27 – The Washington Senators defeat the Cleveland Indians 19–6. Indians starterRay Caldwell lasts just 1.1 innings, and is replaced by George Uhle, who gives up four hits and a walk in only a third of an inning of work. Tony Faeth picks up the third out of the second inning to stop the bleeding after the Senators have plated twelve runs. In all, the Senators collect 22 hits as every starter, including pitcherEric Erickson collects at least one hit.
August 13 – The New York Yankees complete a three-game sweep of the Cleveland Indians to move within a half game of first place.
The Detroit Tigers defeat the Boston Red Sox, 13–12, in 12 innings, despite a major-league record 20 BoSox receiving walks. Eight Tigers also walk to set another ML record of 28 walks in an extra-inning game.
St. Louis Browns first basemanGeorge Sisler goes four-for-five in the Browns' 17–6 victory over the Philadelphia Athletics to raise his average to .400. Sisler will end the season with a .407 batting average.
After having spent most of the season in the minors, and having logged only ten innings pitched all season, Pittsburgh Pirates pitcher Jimmy Zinn pitches all twelve innings in the Pirates' 2–1 extra innings victory over the St. Louis Cardinals. Zinn gives up just six hits in his twelve innings of work.
The Boston Red Sox defeat the Philadelphia Athletics 4–2, handing Connie Mack's team their 100th loss of the season.
September 27 – Babe Ruth hits two home runs, and accounts for all three runs scored in the New York Yankees' 3–0 victory over the Philadelphia Athletics. The two home runs bring his season total to 53. He hits his 54th, and final, home run two days later.
October 1 – The Chicago Cubs' Pete Alexander pitches 17 innings to earn his National League leading 27th victory. Only one of the two runs Alexander surrenders to the St. Louis Cardinals is earned, lowering his ERA to 1.91 for the season, which also leads the league.
Jim Bagby and the Cleveland Indians defeat the Detroit Tigers 10–1 for Bagby's 31st victory of the season.
At Forbes Field, the Pittsburgh Pirates and Cincinnati Reds play the last major league tripleheader, with Cincinnati winning the first two games, 13–4 & 7–3, and Pittsburgh winning the third 6–0 in six innings.
October 6 – The Brooklyn Robins even the World Series at a game apiece with a 3–0 shutout against the visiting Cleveland Indians. Burleigh Grimes is credited with the shoutout, holding Cleveland to only seven hits and four walks while striking out two. Brooklyn right fielder Tommy Griffith goes 2-for-4 with two RBI. Jim Bagby, the losing pitcher, gave up three runs and seven hits in six innings of work.
October 7 – The host Brooklyn Robins beat the Cleveland Indians, 2–1, to take a 2–1 advantage in the World Series. The Robins took an early 2–0 lead in the bottom of the first inning, when leadoff hitter Ivy Olson walked and Tommy Griffith reached base on an error, followed by RBI-singles by Zack Wheat and Hy Myers. The only Cleveland run came in the fourth, after Tris Speakerdoubled to left field and scored on an error. Robins' starter Sherry Smith pitched all the way, giving up an unearned run on three hits and two walks, while striking out two. Ray Caldwell was credited with the loss.
October 10 – At League Park, the Cleveland Indians beat the Brooklyn Robins 8–1 in Game 5 of the World Series to take a 3–2 lead in the Classic, in one of the most unusual games in Series history. This game recorded the only triple play ever made in postseason play, the first Series grand slam, and the first Series home run hit by a pitcher. The triple-header was unassisted and turned by Cleveland second baseman Bill Wambsganss, while the grand slam was hit by Indians outfielder Elmer Smith and the home run belted by Cleveland starterJim Bagby, who earned the victory. Beside this, Brooklyn outhit Cleveland, 13-to-12, in a lost cause. Burleigh Grimes was charged with the loss.
October 11 – The Cleveland Indians put themselves one win away from their first World Championship title, after beating the Brooklyn Robins, 1–0, in Game 6 of the World Series at Cleveland League Park. Facing his former team, Duster Mails pitched a sterling three-hit shutout with four strikeouts and two walks. The only run of the game came in the bottom of the sixth inning, when Tris Speaker hit a two-out single and scored on a double by George Burns. The lack of run support by the Robins made a hard-luck loser out of their starter Sherry Smith, who gave up a run on seven hits in a complete-game defeat.
November 12 – MLB owners unanimously elect Kenesaw Mountain Landis chairman for seven years. The owners' action comes in direct response to the Black Sox Scandal, which threatens the integrity of the game. Landis accepts, but only as sole baseball commissioner with final authority over the players and owners, while remaining a federal judge with his $7,500 federal salary deducted from the baseball salary of $50,000.
February 2 – Frank Quinn, 43, outfielder for the 1899 Chicago Orphans of the National League.
February 5 – Tom Catterson, 35, outfielder who played from 1908 through 1909 for the Brooklyn Superbas of the National League.
February 5 – Ed Siever, 44, pitcher who posted an 83–83 record and a 2.60 earned run average for the Detroit Tigers and St. Louis Browns, while leading the American League pitchers with 1.91 ERA in 1902.
February 6 – Jack Lapp, 35, backup catcher who hit .263 in nine seasons for the Philadelphia Athletics (1908–1915) and Chicago White Sox.
February 11 – Ray Boyd, 33, pitcher who played from 1910 to 1911 with the AL St. Louis Browns and NL Cincinnati Reds.
February 12 – Mike Goodfellow, 53, National League outfielder for the 1887 St. Louis Browns and the 1888 Cleveland Blues.
February 13 – John Shoupe, 68, pitcher and infielder in part of three seasons for the Troy Trojans (NL, 1879), St. Louis Brown Stockings (AA, 1882) and Washington Nationals (UA, 1884).
February 14 – Andy Sullivan, 35, shortstop for the 1904 Boston Beaneaters of the National League.
March 1 – Harry Jordan, 47, pitcher who went 1–2 with a 4.15 ERA for the Pittsburgh Pirates from 1894 to 1895.
March 5 – Alex Farmer, 42, catcher for the 1908 Brooklyn Superbas of the National League.
March 10 – Charlie Briggs, 59, second baseman and outfielder who played for the Chicago Browns of the Union Association during the 1884 season.
March 11 – Ed Poole, 44, National League pitcher who played from 1902 through 1904 for the Pittsburgh Pirates, Cincinnati Reds and Brooklyn Superbas.
April 2 – Matty McIntyre, 39, outfielder for the Philadelphia Athletics, Detroit Tigers and Chicago White Sox between 1901 and 1912, who led the American League in runs, singles and times on base in the 1908 season.
April 18 – George McMillan, 56, Canadian outfielder for the 1890 New York Giants of the National League.
May 1 – Joe Leonard, 25, third baseman for the Pittsburgh Pirates, Cleveland Indians, and Washington Senators between the 1914 and 1920 seasons.
May 8 – Bill McTigue, 27, pitcher who went 2–5 in 27 games with the Boston Rustlers/Braves (1911/1912–1913) and Detroit Tigers (1916).
May 23 – Doc Kennedy, 66, National League catcher who hit .260 in 160 games for the Cleveland Blues and Buffalo Bisons from 1879 to 1883.
June 19 – Ed Barry, 37, pitcher for the Boston Americans from 1905 through 1907.
July 19 – John Hinton, 44, third baseman for the 1901 Boston Beaneaters of the National League.
July 20 – Bill O'Neill, 40, Canadian shortstop for the Boston Americans, Washington Senators and Chicago White Sox between 1904 and 1906, who committed six errors in a single game in 1904 to become the only 20th century big leaguer to accomplish this dubious feat.
July 23 – Buttercup Dickerson, 62, outfielder for eight teams from 1878 to 1885. Officially the first Italian American to play Major League Baseball.
August 1 – Frank Norton, 75, outfielder/third baseman for the 1871 Washington Olympics of the National Association.
August 4 – Frank Fennelly, 60, shortstop for four different teams from 1884 to 1890, who led the National League for the most RBI in 1885
August 12 – Elmer Horton, 48, pitcher for the 1896 Pittsburgh Pirates and the 1898 Brooklyn Bridegrooms of the National League.
August 17 – Ray Chapman, 29, shortstop for the Cleveland Indians since 1912 who batted .300 three times, led American League in runs and walks in 1918.
August 27 – Toby Lyons, 51, pitcher for the 1890 Syracuse Stars of the American Association.
August 29 – Jimmy Peoples, 56, catcher who played from 1884 through 1889 for the Cincinnati Red Stockings, Brooklyn Grays/Bridegrooms and Columbus Solons.
August 31 – John Ricks, 52, third baseman for the St. Louis Browns of the National League in the 1891 and 1894 seasons.
September 5 – Jerry Turbidy, 68, shortstop who played for the Kansas City Cowboys of the Union Association in 1884.
September 11 – Bill Hallman, 53, second baseman, mainly with the Phillies, who batted .300 and scored 100 runs four times each
September 17 – Charlie Eden, 65, outfielder in parts of four parts for the Chicago White Stockings, Cleveland Blues and Pittsburgh Alleghenys, who led the National League in total bases and extrabase hits in 1879.
September 23 – Doc Curley, 46, second baseman for the 1899 Chicago Orphans of the National League.
September 28 – Phil Reardon, 36, outfielder for the 1906 Brooklyn Superbas of the National League.
September 29 – Mark Creegan, 50, outfielder for the 1884 Washington Nationals of the Union Association.
October 2 – Walter Hackett, 63, shortstop who played for the 1884 Boston Reds in the Union Association and the 1885 Boston Beaneaters in the National League.
October 9 – Carl Vandagrift, 37, utility infielder for the 1914 Indianapolis Hoosiers of the Federal League.
November 30 – Lou Meyers, 60, catcher/outfielder for the 1884 Cincinnati Outlaw Reds of the Union Association.
December 9 – George Browne, 44, outfielder for seven different teams in a span of eleven seasons, and a member of the 1905 New York Giants World Champions.
December 16 – Dick Bayless, 37, right fielder for the Cincinnati Reds in 1908.
December 27 – Harvey Cushman, 43, pitcher for the 1902 Pittsburgh Pirates.