Born in Montreal, Mantha was a three-time Stanley Cup winner - 1924, 1930(Captain), 1931(Captain). He played fourteen NHL seasons from 1923–24 to 1936–37, with all but four games as a Montreal Canadiens player. He was the captain of the Montreal Canadiens from 1926–27 to 1931–32 and from 1933–34 to 1935–36. Mantha then worked as a linesman and referee for the AHL and NHL. He then coached the junior league Montreal Concordia Civics, Montreal Nationale (1943 to 1945), Verdun Maple Leafs (1945 to 1947), and St. Jerome Eagles (1947 to 1948).