| Year | Title | Role | Notes |
| 1959 | Anouilh's Antigone | Haemon |
| 1961 | Sir Francis Drake | Lord Oakshott | Episode: "The English Dragon" |
| 1963 | The Outer Limits | Gwyllm Griffiths | Episode: "The Sixth Finger" |
| 1964 | The Travels of Jaimie McPheeters | Prophet | Episode: "The Day Of The Search" |
| Perry Mason | Phillipe Bertain | Episode: "The Case of the Fifty-Millionth Frenchman" |
| The Great Adventure | Captain Hanning | 2 episodes: "Kentucky's Bloody Ground The Siege of Boonesborough" |
| The Outer Limits | Tone Hobart | Episode: "The Forms of Things Unknown" |
| Profiles in Courage | John Adams | Episode: "John Adams" |
| 1964–1968 | The Man from U.N.C.L.E. | Illya Kuryakin | Main cast |
| 1965 | Hullabaloo | Host | Credited as Dave McCallum Episode: "Show 21" |
| 1966 | Please Don't Eat the Daisies | Illya Kuryakin | Episode: "Say U.N.C.L.E." |
| 1969 | Hallmark Hall of Fame | Hamilton Cade, Kenneth Canfield | 2 episodes: "Teacher, Teacher The File on Devlin" |
| 1970 | Hauser's Memory | Hillel Mondoro | Science fiction television film Screenplay by Adrian Spies was based on a 1968 novel of the same name which was a sequel to the novel Donovan's Brain. |
| 1971 | Night Gallery | Dr. Joel Winter | Episode: "The Phantom Farmhouse" |
| The Man and the City | Guest | Episode: "Pipe Me A Loving Tune" |
| 1972–1974 | Colditz | Simon Carter | Main cast |
| 1973 | Frankenstein: The True Story | Dr. Henry Clerval | Television film |
| The Six Million Dollar Man | Alexi Kaslov | Episode: "Wine, Women and War" |
| 1975–1976 | The Invisible Man | Daniel Westin | 12 episodes; Main cast |
| 1978 | Kidnapped | Alan Breck Stewart | Miniseries |
| 1979–1982 | Sapphire & Steel | Steel | Main cast |
| 1982 | Strike Force | Roderick Howard Hadley III | Episode: "Ice" |
| Hart to Hart | Geoffrey Atterton | Episode: "Hunted Harts" |
| 1983 | As the World Turns | Maurice Vermeil | Contract role |
| Return of the Man from U.N.C.L.E. | Illya Kuryakin | Television film |
| 1984 | The Master | Castile | Episode: "Hostages" |
| 1986 | Hammer House of Mystery and Suspense | Frank Lane | Episode: "The Corvini Inheritance" |
| The A-Team | Ivan | Episode: "The Say U.N.C.L.E. Affair" |
| 1987 | Matlock | Phil Dudley | Episode: "The Billionaire" |
| 1988 | Alfred Hitchcock Presents | Lieutenant Cavanaugh | "Murder Party" |
| Monsters | Boyle / The Feverman | Episode: "The Feverman" |
| The Man Who Lived at the Ritz | Charlie Ritz | Television film |
| 1989 | Murder, She Wrote | Cyril Grantham | Episode: "From Russia...With Blood" |
| Mother Love | Sir Alexander "Alex" Vesey | Main cast |
| McCloud | Inspector Craig | Television film titled The Return of Sam McCloud |
| 1990 | Murder, She Wrote | Drew Garrison | Episode: "Deadly Misunderstanding" |
| Boon | Simon Bradleigh | Episode: "The Belles of St. Godwalds" |
| Lucky Chances | Bernard Dimes | Miniseries |
| Father Dowling Mysteries | Sir Robert | Episode: "The Royal Mystery" |
| 1991–1992 | Trainer | John Grey | Main cast |
| 1991 | Cluedo | Professor Plum | Game show |
| 1993 | seaQuest DSV | Frank Cobb | Episode: "seaWest" |
| 1994 | Babylon 5 | Dr. Vance Hendricks | Episode: "Infection" |
| Titanic: The Complete Story | | Narrator |
| Heartbeat | Cooper | Episode: "Arms and the Man" |
| 1994–1995 | Scavengers | Narrator | Voiceover |
| 1995 | VR-5 | Dr. Joseph Bloom | Main cast |
| 1996 | Mr. & Mrs. Smith | Ian Felton | Episode: "The Impossible Mission" |
| 1997 | Law & Order | Craig Holland | Episode: "Past Imperfect" |
