Henry John Gruber (December 14, 1863 – September 26, 1932) was an American professional baseball pitcher who played from 1885 through 1895. A right-hander, he played five years in Major League Baseball with the Detroit Wolverines (1887–88) and Spiders (1889, 1891) of the National League and the Cleveland Infants (1890) of the Players League. He won 61 games and lost 78 in his career, and had a 3.67 earned run average (ERA).