February 17 – The Missouri Court of Appeals holds that a fan injured by a foul ball at a 1910 Kansas City Blues game was not entitled to damages from the team since he had chosen to sit in a seat unprotected by a screen when such seats were available, establishing the Baseball Rule in United States tort law.
October 11 – The Philadelphia Athletics defeat the New York Giants, 3-1, in Game 5 of the World Series to win the World Championship, four games to one. The Giants thus become the second club, following the Detroit Tigers of 1907–1909, to lose three consecutive World Series; and, to date, the last to do so.
November 2 – George Stovall, former St. Louis Browns player-manager, became the first Major Leaguer to jump to the outlaw Federal League after signing a contract to manage the Kansas City Packers.
January 6 – Jack Boyle, 46, catcher/first baseman who hit.253 with 23 home runs and 570 RBI for five different teams in three leagues from 1886 to 1898.
January 14 – Hal O'Hagan, 43, first baseman for the 1892 Chicago Orphans and for the New York Giants, Cleveland Bronchos and Washington Senators in the 1902 season.
March 28 – Clare Patterson, 25, left fielder for the 1909 Cincinnati Reds of the National League.
April–June
April 16 – Jerry Harrington, 45, National League catcher who hit.227 in 189 games with the Cincinnati Reds and Louisville Colonels.
April 18 – Roscoe Miller, 36, pitcher for the Detroit Tigers, New York Giants and Pittsburgh Pirates, who became the first 20-game winner in Tigers history.
April 23 – Charlie Pabor, 66, player-manager for four teams of the National Association from 1871 through 1875.
May 1 – Charlie Reynolds, 55, pitcher for the 1882 Philadelphia Athletics of the American Association.
May 13 – John O'Brien, 46, Canadian second baseman who hit.256 in 501 games for six National League teams from 1891 to 1899.
May 14 – Dennis Coughlin, 69, outfielder for the 1872 Washington Nationals of the National Association; best remembered as the only major leaguer who was wounded in combat during the Civil War.
May 18 – The Only Nolan, 55, pitcher who posted a 23-52 record and a 2.98 ERA in 79 games with four teams between 1878 and 1875.
May 18 – Charlie Robinson, 56, American Association catcher who played for the Indianapolis Hoosiers and Brooklyn Grays.
June 5 – Chris von der Ahe, 61, owner of the St. Louis Browns from 1882 to 1898, who greatly developed the entertainment aspect of the sport with fan-friendly promotions and ballpark attractions, and also presided over first team to win four straight pennants.
June 30 – George Tidden, 56, sports editor in New York since 1895.
July–September
July 13 – Dan Sweeney, 45, outfielder for the 1895 Louisville Colonels of the National League.
July 17 – Pat Scanlon, Canadian outfielder who played in 1884 with the Boston Reds of the Union Association.
July 19 – Jiggs Donahue, 34, a standout at first base in the early years of the American League, and a key member of the 1906 White Sox that won their cross-town rival Cubs in the only all-Chicago World Series ever played.
July 28 – John Greenig, 65, pitcher for the 1888 Washington Nationals of the National League.
August 8 – John Gaffney, 58, the sport's first great umpire, officiating for twelve seasons in three leagues between 1884 and 1900; managed Washington team in 1886-87, and officiated in 1887-88-89 championship series, pioneering use of multiple umpires in games.
August 14 – Chummy Gray, 40, pitcher who posted a 3-3 record and a 3.44 ERA for the Pittsburgh Pirates in 1899.
August 25 – Red Donahue, 40, pitcher who won 20 games three times with the Phillies and Browns and led the National League in complete games, while collecting 164 career wins and a no-hitter.
September 3 – Charlie Householder, 59, first baseman/catcher who played in two Major League seasons, 1882 and 1884.
September 15 – Frank Hough, 56, sports editor in Philadelphia who helped organize the Athletics American League franchise in 1901
September 24 – Fred Roat, 45, National League third baseman for the Pittsburgh Alleghenys and Chicago Colts.
October–December
October 8 – Elmer Cleveland, 51, third baseman who hit.255 in 80 games with four clubs in three different leagues between 1884 and 1891.
October 13 – Mike Heydon, 39, catcher who played from 1898 through 1907 for the Senators, Cardinals, WhiteSox and Orioles.
October 24 – Dan Shannon, 48, player and manager during his three-year career with the Colonels/Giants/Statesmen/Athletics from 1889 to 1891.
November 15 – Monte McFarland, 41, pitcher who played for the National League Chicago Colts in 1895 and 1896.
December 24 – Chief Sockalexis, 42, right fielder for the 1897-99 Cleveland Spiders, who was the first Native American to play in the major leagues.
December 26 – Frank O'Connor, 46, pitcher for the 1893 Philadelphia Phillies.
December 30 – Joe Neale, 47, American Association pitcher for the St. Louis Browns and Louisville Colonels.