Gustavus Heinrich Schmelz (September 26, 1850 – October 14, 1925) was an American manager in Major League Baseball for the Columbus Buckeyes (1884), (1887–89), and Columbus Solons (1890–91) of the American Association, and for the St. Louis Maroons (1886), Cleveland Spiders (1890) and Washington Senators (1894–97) of the National League. He was regarded as a player's manager, but his camaraderie with his players did not translate to pennants, as he never finished higher than second place. His lifetime managerial record was 624–703 (.470).
He died in his birthplace of Columbus, Ohio at age 75 and is buried at Green Lawn Cemetery.