Williamson spent 27 years coaching in the NFL and another 18 tutoring players on the collegiate level. He became the fourth head coach in Buccaneers franchise history on December 3, 1990, remaining in that position for the remainder of the 1990 season and all of 1991. Williamson's final coaching stop was his longest one, as he was an assistant for the Carolina Panthers from 1995-2009. The Panthers' team web site said that Williamson died after a brief illness.
Williamson first came to the Buccaneers in 1987 to guide the wide receivers under new Tampa Bay Head Coach Ray Perkins, after starting his NFL career in Kansas City.