John Wesley "Jack" Coombs (November 18, 1882 – April 15, 1957), nicknamed "Colby Jack" after his alma mater, was an American professional baseball player.
He played in Major League Baseball as a pitcher for the Philadelphia Athletics (1906–14), Brooklyn Robins (1915–18), and Detroit Tigers (1920).
Coombs set a number of American League and World League records which still stand and, when he won 31 games while losing nine in 1910, he became one of only 13 pitchers to win 30 games in a season since 1900.