| Year Title Role Notes | |
| 1955 The Vise Tony Mason "1 episode (""Gift from Heaven"")" | |
| 1958 The Vise Vance "1 episode (""Blood in the Sky"")" | |
| 1958 Armchair Theatre Jack 'Pal' Smurch "1 episode (""The Greatest Man in the World"")" | |
| 1959 Brand Priest Brand Henrik Ibsen play | |
| 1961 Armchair Theatre Nicholai Soloviov "1 episode (""The Man Out There"")" | |
| 1960–62 1964–67 Danger Man John Drake 39 + 47 episodes. Also directed three episodes. | |
| 1963 Walt Disney's Wonderful World of Color Doctor Christopher Syn/ Scarecrow of Romney Marsh 3 episodes | |
| 1967–68 The Prisoner Number Six 17 episodes. Also directed five episodes. | |
| 1969 Journey into Darkness Host Made-for-TV film | |
| 1974 Columbo Colonel Lyle C. Rumford "1 episode (""By Dawn's Early Light"")" | |
| 1975 Columbo Nelson Brenner "1 episode (""Identity Crisis""). Also directed." | |
| 1976 Columbo N/A "1 episode (""Last Salute to the Commodore"") – director" | |
| 1977 Rafferty Doctor Sid Rafferty 13 episodes. Also directed one episode. | |
| 1979 The Hard Way John Connor Made-for-TV film | |
| 1983 Jamaica Inn Joss Merlyn - | |
| 1985 American Playhouse Chief magistrate "3 episodes (""Three Sovereigns for Sarah"" parts I, II & III)" | |
| 1987 Murder, She Wrote Oliver Quayle "1 episode (""Witness for the Defense"")" | |
| 1990 Columbo Oscar Finch "1 episode (""Agenda for Murder""). Also directed." | |
| 1998 Columbo Eric Prince """Ashes to Ashes"". Also directed." | |
| 2000 Columbo N/A "1 episode (""Murder with Too Many Notes"") – director" | |
| 2000 The Simpsons Number Six "1 episode (""The Computer Wore Menace Shoes"")" | |