July 8 – The New York Yankees are shut out, 4–0, by Rube Walberg and the Philadelphia Athletics. It is the Yankees' seventh loss in a row, and second shut out in that stretch (July 4 against the Washington Senators). They are the only two shut outs the Yankees suffer all season.
September 20 – Bill Terry goes four-for-five in the first game of a double header and two-for-four in the second to raise his season average to .402. He goes five-for-seven in a double header the next day to see his average go as high as .406. He ends the season with a .401 batting average. He is the last National Leaguer to bat over .400.
October 1 – The Philadelphia Athletics defeat the St. Louis Cardinals 5-2 in game one of the 1930 World Series despite being out hit 9-5. All five hits by the A's are for extra bases (a double, two triples & two home runs).
October 4 – Bill Hallahan gets out of a bases loaded jam in the first inning by striking out Bing Miller. From there, he settles in, and leads the Cardinals to a 5–0 victory in game three of the World Series.
October 5 – Jimmie Dykes' throwing error in the fourth leads to two unearned runs as the Cardinals even up the series with a 3–1 victory.
October 6 – Jimmie Foxx breaks open a scoreless game with a two run home run in the ninth to give the A's the 2–0 victory in game five.
October 8 – The Philadelphia Athletics defeated the St. Louis Cardinals, 7–1, in Game six of the World Series to win their second consecutive World Championship, and fifth overall, four games to two. This would be the Athletics' last World Series championship in the city of Philadelphia.
November 10 – Veteran pitcher Hippo Vaughn is reinstated by Judge Landis after eight years of ineligibility. Vaughn, who had lost a double no-hitter duel to Fred Toney in the 1917 season, had jumped the Chicago Cubs in 1922. Vaughn chose to pitch for a semi-professional team following a salary dispute with Chicago. He will go to spring training with the Cubs in 1931 but will fail to make the team at age 43.
January 8 – Charlie Flannigan, 38, third baseman/outfielder for the 1913 St. Louis Browns.
January 20 – Jumbo Schoeneck, 57, first baseman for the Chicago Browns, Pittsburgh Stogies, Baltimore Monumentals and Indianapolis Hoosiers from 1884 to 1889, who finished in the top ten in 10 offensive categories of the Union Association in his rookie season.
January 25 – Spencer Heath, 36, relief pitcher for the 1920 Chicago White Sox.
January 30 – Rip Hagerman, 41, pitcher for the Chicago Cubs (1909) and Cleveland Indians (1914–1916).
March 11 – Bob Barr, 73, pitcher who played for six different teams of the American Association and National League between 1883 and 1891.
March 12 – Jack Powell, 70, pitcher who posted 245 wins and a 2.97 ERA with four teams from 1897 to 1904 .
March 15 – George Townsend, 62, catcher who played from 1887 to 1891 with the Philadelphia Athletics and Baltimore Orioles of the American Association.
March 21 – Bill Fagan, pitcher for the New York Metropolitans (1887) and Kansas City Cowboys (1888) of the American Association.
March 25 – Bill Krieg, 71, catcher/outfielder/third baseman for the St. Louis, Pittsburgh, Chicago, Brooklyn and Washington teams from 1884 to 1887, who also won three minor league batting titles in the 1880s.
April 5 – Jack McGeachey, 65, backup outfielder who hit .245 with 164 stolen bases in 608 games for six teams from 1886 to 1891.
April 11 – Wayland Dean, 27, pitcher who posted a 24–36 record with a 4.87 ERA for the Giants, Phillies and Cubs from 1924 to 1927.
April 14 – Frank Kitson, 60, pitcher who won 128 games with a 3.18 ERA for six teams from 1898 to 1907.
April 14 – John B. Sheridan, 61, sportswriter for St. Louis newspapers whose column "Back of the Home Plate" appeared in The Sporting News for many years.
April 18 – Jack Stivetts, 62, pitcher for St. Louis Cardinals, Boston Beaneaters and Cleveland Spiders from 1889 to 1899, who collected six 20-win seasons, including 30-win campaigns in 1891 and 1892, and also hurled a no-hitter and won two games in the 1892 championship playoff.
April 23 – Rube Manning, 46, pitcher who posted a 22-32 record with a 3.14 ERA in 84 games for the New York Yankees from 1907 through 1910.
April 23 – Larry Twitchell, 66, outfielder and one of the early sluggers in major league history, who played from 1886 through 1894 with seven different teams, most prominently for the Detroit Wolverines.
April 26 – Harry Mace, 63, pitcher for the 1891 Washington Statesmen.
September 1 – John Reccius, 70, pitcher and center fielder for the 1882–1883 Louisville Eclipse.
September 7 – Mickey Keliher, 40, first baseman for the Pittsburgh Pirates from 1911 to 1912.
September 14 – Jim McCauley, 67, backup catcher for the St. Louis Browns, Buffalo Bisons, Chicago White Stockings and Brooklyn Grays from 1884 to 1886.
September 19 – Arlie Pond, 57, pitcher for the Baltimore Orioles from 1895 to 1898, as well as a doctor in the U.S. Army between 1898 and 1919.
September 25 – Joe Wilhoit, 44, right fielder for the Boston Braves, Pittsburgh Pirates, New York Giants and Boston Red Sox from 1916 to 1919, who posted the longest hitting streak in baseball history with 69 games in 1919, while playing for the Wichita Jobbers of the Western League.
December 3 – Harry Baumgartner, 38, relief pitcher who went 0–1 in nine games for the 1920 Detroit Tigers.
December 5 – Ben Guiney, 72, backup catcher for the Detroit Wolverines during the 1883 and 1884 seasons.
December 9 – Rube Foster, 51, pioneer and driving force in the Negro Leagues, as owner and manager of the Chicago American Giants from 1911 to 1925, who in 1920 founded the first stable Negro League, the Negro National League, and won its first three pennants, also regarded as the premier pitcher in black baseball in the century's first decade.
December 9 – Dave Rowe, 76, center fielder for five teams in six seasons between 1877 and 1888, who also managed the Kansas City Cowboys in 1885 and 1888.
December 14 – Al Hubbard, 70, catcher/shortstop for the 1883 Philadelphia Athletics.
December 25 – Fred Clement, 63, shortstop for the 1890 Pittsburg Alleghenys.
December 29 – Sandy Piez, 42, backup outfielder who spent most of his career as a specialist pinch-runner with the 1914 New York Giants.
December 29 – Ginger Shinault, 38, backup catcher who hit .295 in 35 games for the Cleveland Indians from 1921 to 1922.
December 29 – George Stutz, 37, shortstop who appeared in six games with the 1926 Philadelphia Phillies.