Before 7th Heaven, Collins was known for his roles as Commander Willard Decker in the 1979 film Star Trek: The Motion Picture and fighter pilot Jake Cutter in the ABC television series Tales of the Gold Monkey.

[3][4] Collins was raised with his two older brothers in Hastings-on-Hudson, New York, and attended Amherst College in Massachusetts, graduating cum laude.

He also played the lead role opposite Lauren Hutton in the television film The Rhinemann Exchange (1977), based on Robert Ludlum's bestselling novel.

[10] On ABC's Brothers & Sisters, he played a potential love interest for Ron Rifkin's character Saul Holden.

[11][12] In 2013, Collins began appearing in the NBC series Revolution as Dr. Gene Porter, the leader of the town of Willoughby and father of Rachel Matheson (played by Elizabeth Mitchell).

[24][25] In a December 2014 interview with People, Collins admitted that he committed "inappropriate sexual conduct with three female minors" in 1973, 1982, and 1994.