John "Jack" Sullivan (August 29, 1870 – Unknown death) was a Canadian lacrosse player who competed in the 1904 Summer Olympics for the United States. Sullivan was born in Cobourg, Ontario. In 1904 he was member of the St. Louis Amateur Athletic Association which won the silver medal in the lacrosse tournament. References External links 1870 births Year of death missing Canadian lacrosse players Olympic silver medalists for the United States in lacrosse Lacrosse players at the 1904 Summer Olympics Medalists at the 1904 Summer Olympics