April 11 – At the Polo Grounds, Babe Ruth of the Boston Red Sox pitches a three-hitter in shutting down the New York Yankees on Opening Day, 1–0. Ruth's performance marks the start of good things to come. He will win 24 games this year, while leading the American League with 35 complete games.
May 7 – Babe Ruth pitches a shutout and drives in the game's only run on a sacrifice fly as the Red Sox top Walter Johnson and the Senators, 1-0.
June 23 – Ernie Shore of the Boston Red Sox pitched the most notable game of his career leading his team to a 4–0 win against the Washington Senators. Babe Ruth started the game for Boston but walked the leadoff hitter, Ray Morgan. Ruth then engaged in a heated argument with home plate umpire, Brick Owens,who tossed Ruth out of the game. Then Shore came in to the game to relieve Ruth. Morgan was caught stealing, and Shore retired the next 26 Senators he faced. At the time, Shore was credited with a perfect game, but since then, the criteria have been revised, and Shore's name has been removed from the record books, although he still gets credit for a combined no-hitter.
July 6 – The Chicago White Sox put a stop to Ty Cobb's consecutive-game hitting streak, halting it at 35.
January 3 – Rynie Wolters, 74, Dutch pitcher and outfielder who hit .318 and posted a 19-23 record with the New York Mutuals, Cleveland Forest Citys and Elizabeth Resolutes between 1871 and 1873.
January 10 – Jack McFetridge, 47, pitcher who played in 1890 and 1903 with the Philadelphia Phillies of the National League.
January 13 – Jim Garry, 47, pitcher for the 1893 Boston Beaneaters.
January 16 – Charlie Geggus, 54, pitcher who posted a 10-9 record and a 2.54 ERA for the 1884 Washington Nationals of the Union Association.
January 17 – Pat McCauley, 46, backup catcher who played between 1893 and 1903 for the St. Louis Browns, Washington Senators and New York Highlanders.
January 19 – Charlie Enwright, 29, shortstop who played for the 1909 St. Louis Cardinals.
January 26 – Jim McGuire, 41, shortstop for the 1901 Cleveland Blues of the American League.
January 30 – Cyclone Ryan, 51, Irish pitcher and first baseman who played for the 1887 New York Metropolitans and the 1891 Boston Beaneaters.
January 31 – Pete O'Brien, 39, second baseman for the Cincinnati Reds, St. Louis Browns, Cleveland Naps and Washington Senators between 1901 and 1907.
February 7 – Tim Murnane, 64, first baseman and center fielder in the early years of professional baseball who became president of the New England League and went on to a distinguished tenure as sports editor of The Boston Globe for over 30 years, serving as one of the sport's leading advocates.
February 18 – Charlie Fisher, 64, third baseman who played for the Kansas City Cowboys and the Chicago Browns of the Union Association in the 1884 season.
February 23 – Art Weaver, 37, catcher and infielder who played with the Cardinals, Pirates, Browns and White Sox between 1902 and 1908.
February 28 – Parson Nicholson, 53, second baseman who played for the Detroit Wolverines, Toledo Maumees and Washington Senators between 1888 and 1895.
March 4 – Joe Dowie, 51, backup outfielder for the 1889 Baltimore Orioles of the National League.
March 9 – Cooney Snyder, 45, Canadian catcher who played for the 1898 Louisville Colonels.
March 15 – John Munce, 69, outfielder for the 1884 Wilmington Quicksteps of the Union Association.
March 27 – Willie Jensen, 27, American League pitcher who played for the 1912 Detroit Tigers and the 1914 Philadelphia Athletics.