Roberts signed a contract with Columbia Pictures in 1957 and made his film debut a year later as one of Burl Ives' contentious sons in "Desire Under the Elms" (1958). The film was nominated for a Best Cinematography Academy Award. He also landed a character role in "The Sheepman" (1958), opposite Glenn Ford and Shirley MacLaine, and continued to guest-star on television shows such as episodes of "Shirley Temple Storybook Theater" ("The Emperor's New Clothes", "Rumplestiltskin", "The Sleeping Beauty", and "Hiawatha"), the live-broadcast "Matinee Theater", where he starred again in Shakespeare's "Much Ado About Nothing", and in "The Heart's Desire". This was followed by appearances in "Trackdown", "Buckskin", and episodes of "Zane Grey Theater". Roberts guest-starred as Captain Jacques Chavez on the NBC adventure series "Northwest Passage" (1958). He appeared with fellow guest star Fay Spain in the 1958 episode "Pick Up the Gun" of "Tombstone Territory" and played the lead villain in the 31st episode ("Hey Boy's Revenge") of "Have Gun – Will Travel", portraying a killer boss exploiter of Chinese coolie laborers.