Roberts played Jim Conrad, the lead role, in the 1971 TV movie that served as a pilot for the series "San Francisco International Airport", though the role was played by Lloyd Bridges in the actual episodes of the series. Roberts guest-starred in TV shows such as "The Girl from U.N.C.L.E.," "The Virginian," "The Big Valley," "Lancer," ' (4 episodes), "Have Gun Will Travel", "Marcus Welby, M.D.," "The Wild Wild West," "Ironside" (2 episodes), "The Rockford Files," "Gunsmoke," "Mannix," "Vega$," "The Odd Couple," "Hawaii Five-O," "The Love Boat," "Hotel", "The Hardy Boys/Nancy Drew Mysteries," "Nakia," "Night Gallery," "The Bold Ones," "The Quest," "Police Story," "Most Wanted," "Westside Medical," "Man From Atlantis," "Jigsaw John," "Sixth Sense," "Quincy, M.E. " "The Feather and Father Gang," "Hawkins," "Men from Shiloh," "Perry Mason," "Wide World of Mystery," and "The Six Million Dollar Man," and appeared in miniseries, including "Captains and the Kings," "Centennial," "The Immigrants" and "Around the World in 80 Days." He starred in two cult films, "Four Rode Out" (1971) and "Kashmiri Run" (1970), directed by the veteran TV director John Peyser, and other feature films, including "The Magic of Lassie" (1978). He co-starred or was featured in several TV movies, including, "The Adventures of Nick Carter," "Dead Man on the Run," "Assignment: Munich", "The Night Rider," "The Silent Gun," "The Lives of Jenny Dolan", "The Deadly Tower," "Hot Rod," "Desperado," "The Bravos," and '.