Frank Henry Mountain (May 17, 1860 – November 19, 1939) was an American baseball player from 1880 to 1886. He played seven seasons in Major League Baseball, principally as a pitcher (143 games), outfielder (36 games) and first baseman (18 games). He played for six different major league clubs and saw his most extensive playing time with the Columbus Buckeyes of the American Association, appearing in 128 games for that club during the 1883 and 1884 seasons.