Bill O'Hara may refer to:
Bill O'Hara (baseball) (1883–1931), American Major League Baseball outfielder Bill O'Hara (footballer, born 1879) (1879–1957), Australian rules footballer for St Kilda Bill O'Hara (footballer, born 1880) (1880–1946), Australian rules footballer for South Melbourne Bill O'Hara (sailor) (born 1958), Irish Olympic sailor
See also William O'Hara (1816–1899), Irish-born prelate of the Roman Catholic Church