Nelson was born in Salt Lake City, Utah where he later studied acting at the University of Utah then transferred to New York University's Tisch School of Arts. He has guest starred in television series such as The Rookies (1976, with Michael Forest), Square Pegs (1982, starring Merritt Butrick), Santa Barbara (1985), The Golden Girls (1986, with Sam Anderson), L.A. Law (1988, starring Corbin Bernsen and with Rosalind Allen, Fran Bennett, Jim Jansen, Todd Jeffries, and Christine Rose), Dallas (1989, with Joey Aresco, Ron Canada, and Lance LeGault), Alien Nation (1989, starring Eric Pierpoint, Gary Graham, Michele Scarabelli, Ron Fassler, and with Sam Anderson, Andreas Katsulas, and Joel Swetow, in an episode directed by David Carson), Quantum Leap (1992, starring Scott Bakula and Dean Stock