Bill or William Gannon may refer to: William F. Gannon (1859–1916), American Catholic priest and Jesuit Bill Gannon (baseball) (1873–1927), American baseball player Bill Gannon (Gaelic footballer) (1901–1967), Irish Gaelic footballer Bill Gannon (Irish republican) (1902–1965), member of the Irish Republican Army A fictional character on the American television series Dragnet, played by Harry Morgan William J. Gannon (born 1937), American politician in the state of Iowa Bill Gannon (New Hampshire politician) (born 1962), New Hampshire politician