Williams played for seven seasons and three different teams. As a rookie, he was on the Green Bay Packers when they beat the New York Giants 16–7 in the 1962 NFL Championship Game. He played only seven games for the team the following season before being sent to the San Francisco 49ers. The following year, he joined the Oakland Raiders, where he would spend the next six seasons, including three consecutive AFL title game appearances (1967, 1968, and 1969), along with an appearance in Super Bowl II. In his career, he had 14 interceptions for 240 yards in 95 games played.