William R. Butler (born July 10, 1937 in Berlin, Wisconsin) is a former American football safety in the National Football League for the Green Bay Packers (1959), the Dallas Cowboys (1960), the Pittsburgh Steelers (1961) and the Minnesota Vikings (1962–1964). He played college football at the University of Tennessee at Chattanooga and was drafted in the 19th round of the 1959 NFL Draft. Butler was also selected by the Dallas Cowboys in the 1960 NFL Expansion Draft, but did not make the active roster.