The son of Clyde Ira Selby and Sarah E. McIntyre Selby, he attended West Virginia University in his hometown, earning Bachelor of Science and Master's degrees in theater, followed by a Ph.D. from Southern Illinois University. He would eventually bring his Dark Shadows character to film with the second Dark Shadows movie, Night of Dark Shadows, released in 1971 after the TV series' cancellation. A year before joining Falcon Crest in 1982, he played the villainous Michael Tyronne on the final season of the NBC primetime serial Flamingo Road. In 1989, Selby was very devastated to hear about his co-star's Jane Wyman's medical leave from the show, at the beginning of the ninth and final season on Falcon Crest, that he alongside Lorenzo Lamas and Susan Sullivan (who played Selby's wife), visited the ailing star at the hospital. That same year, his screen-time had been expanded for most of the last season. Long after the series was cancelled, and while co-starring opposite his old friend Jane Alexander in Tell Me You Love Me, Selby was grief-stricken when his co-star, Jane Wyman, had died in 2007, and had delivered his condolences to Wyman's family, according to his website. Selby's movie credits include co-starring roles with Barbra Streisand in Up the Sandbox (1972) and with Ron Leibman in The Super Cops (1974), White Squall, D3: The Mighty Ducks, Raise the Titanic, and Surviving Christmas (2004). He has recently reprised the role of Quentin Collins for a new series of Dark Shadows audio dramas from Big Finish Productions.
His writing includes the plays Lincoln and James and Final Assault as well as the poetry collections My Mother's Autumn and Happenstance.
West Virginia University in 1998 awarded Selby its first Life Achievement Award from the College of Creative Arts, and an honorary doctorate in 2004.
