| Year | Title | Role | Notes |
| 1956 | The United States Steel Hour | Piney Woods | Episode: Bang the Drum Slowly |
| 1956–1957 | Kraft Television Theatre | Various | Episodes: The Long FlightFlying Object at Three O'Clock High |
| 1957 | The Kaiser Aluminum Hour | Lynch | Episode: A Real Fine Cutting Edge |
| Studio One | | Episode: A Walk in the Forest |
| The Alcoa Hour | Eddie Pierce | Episode: The Big Build-Up |
| Alfred Hitchcock Presents | Evan Wallace | Episode: The Diplomatic Corpse |
| 1957–1958 | Matinee Theatre | | Episodes: End of the Rope, Part 1End of the Rope, Part 2Aftermath |
| 1958 | Suspicion | Lee | Episode: The Eye of Truth |
| Hallmark Hall of Fame | Dennis Walsh | Episode: Little Moon of Alban |
| 1960 | Startime | Pat Lawrence | Episode: Incident at a Corner |
| 1964 | Theatre of Stars | Buddy Wren | Episode: The Game with Glass Pieces |
| 1972 | The Bravos | Major John David Harkness | Television Film |
| 1972–1974 | Banacek | Thomas Banacek | |
| 1975 | The Week of Fear | Dr. Jake Goodwin | Television Film |
| Guilty or Innocent: The Sam Sheppard Murder Case | Dr. Samuel Sheppard |
| 1975–1976 | Doctors' Hospital | Dr. Jake Goodwin | |
| 1979 | Crisis in Mid-Air | Nick Culver | Television Film |
| Torn Between Two Lovers | Paul Rasmussen |
| 1982 | Twilight Theatre | |
| 1983–1987 | The A-Team | Colonel John "Hannibal" Smith | |
| 1984 | Tales of the Unexpected | Sergeant Guedo | Episode: The Dirty Detail |
| 1988 | Man Against the Mob | Frank Doakey | Television Film |
| 1989 | Man Against the Mob: The Chinatown Murders |
| 1990 | Night of the Fox | Colonel Harry Martineau/Max Vogel |
| 1994 | Matlock | Max Morgan | Episode: The P.I. (final appearance) |