Earned a BA from Southern Methodist University.
Earned a JD from Memphis State.
Enlisted in the army and served two years.
Has one adult son, Andrew.
In 2009 was profiled in "Character Kings: Hollywood's Familiar Faces Discuss the Art & Business of Acting" by Scott Voisin.
Was originally cast as Joe Camber in Cujo (1983).
He is sometimes confused with fellow character actor Tracey Walter, who has sometimes also played the same type of eccentric Southern lowlifes. Since they have often gone after the same roles, the two actors have actually become friends. Unlike Walter, Sanderson actually hails from the Southeast US.
As o 2017, was semi-retired from acting and residing in Harrisburg, PA. In a 2017 interview with PennLive, he stated that in the mid-2000s he and his wife bought a house there to be closer to her family. However, they liked Pennsylvania so much that they now live there full time.