| Year | Film | Role | Notes |
|---|
| 1966 | Mission: Impossible | Tosk | Episode: "Old Man Out" |
| 1967 | Iron Horse | Dan Patrick | Episode: "Death by Triangulation" |
| 1967-1968 | The Second Hundred Years | Luke/Ken Carpenter | Lead role |
| 1968 | The F.B.I. | Thomas Waters | Episode: "The Intermediary" |
| 1969 | Here Come the Brides | Bass | Episode: "The Firemaker" |
| Mod Squad | Billy Kilgore | Episode: "Fear Is the Bucking Horse" |
| My Friend Tony | Episode: "Welcome Home, Jerry Stanley" |
| 1969-1970 | Mr. Deeds Goes to Town | Longfellow Deeds | Recurring role |
| 1970 | Bracken's World | Ray Wiley | Episode: "A Perfect Piece of Casting" |
| The Virginian | Boss Cooper | Episode: "Gun Quest" |
| The High Chaparral | Dave Redman | Episode: "Too Late the Epitaph" |
| Hogan's Heroes | Captain James Martin | Episode: "Eight O'Clock and All Is Well" |
| The Young Rebels | William Billings | Episode: "Valley of the Guns" |
| The Bold Ones: The Lawyers | Nick Chapman | Episode: "The People Against Doctor Chapman" |
| Love, American Style | Steve | Segment: "Love and Those Poor Crusaders' Wives" |
| Andy | Segment: "Love and the Pen Pals" |
| The F.B.I. | Arthur McBride | Episode: "The Architect" |
| Hawaii Five-O | Harry Kellem | Episode: "The Double Wall" |
| 1971 | The Mary Tyler Moore Show | John Corcoran | Episode: "Just a Lunch" |
| Dan August | Frank Devlin | Episode: "Dead Witness to a Killing" |
| The Name of the Game | Charlie | Episode: "A Capitol Affair" |
| Alias Smith and Jones | Jim Stokely | Episode: "Something to Get Hung About" |
| Love, American Style | Larry | Segment: "Love and the Married Bachelor" |
| Funny Face | Episode: "Four Sided Triangle" |
| Sarge | Tom Flynn | Episode: "A Bad Case of Monogamy" |
| The F.B.I. | James Robert Devlin | Episode: "The Recruiter" |
| Hawaii Five-O | Jerry Rhodes | Episode: "Wednesday, Ladies Free" |
| 1972 | The New Dick Van Dyke Show | Bill Mitchell | Episode: "After the Ball Is Over" |
| Medical Center | Dr. Grainger | Episode: "The Choice" |
| 1973 | Hawaii Five-O | Barry Dean | Episode: "Here Today... Gone Tonight" |
| 1973-1974 | The New Perry Mason | Perry Mason | Starring role |
| 1974 | Medical Center | Scott | Episode: "Adults Only" |
| The Manhunter | Keeley Maxwell | Episode: "The Doomsday Gang" |
| Police Woman | Joey Marr | Episode: "The Stalking of Joey Marr" |
| 1974-1975 | The Six Million Dollar Man | Barney Miller | 2 episodes |
| 1975 | Barnaby Jones | Vince Barrett, Rick Hatfield | Episode: "Doomed Alibi" |
| Cannon | Ed Foster 'Condor' | Episode: "Vengeance" |
| Caribe | Charles Mayfield | Episode: "Lady Killer" |
| Ellery Queen | Tom McKell | Episode: "Too Many Suspects" |
| Medical Story | Raphael Aldrich | Episode: "Woman in White" |
| 1976 | The Invisible Man | Pike | Episode: "Power Play" |
| McNaughton's Daughter | David Borman | Episode: "Love Is a Four-Letter Word" |
| Quincy, M.E. | Harold Fredericks | Episode: "Who's Who in Neverland" |
| The Quest | Nelson Story | Episode: "The Freight Train Rescue" |
| 1977 | The Hardy Boys/Nancy Drew Mysteries | Professor Jack Wall | Episode: "The Mystery of Pirate's Cove" |
| Police Woman | Bishop | Episode: "Guns" |
| 1978 | Lucan | Steven Demaree | Episode: "How Do You Run Forever?" |
| What Really Happened to the Class of '65? | Coach Briggs | Episode: "Class Renegade" |
| 1979 | The Littlest Hobo | Ray Caldwell | Episode: "Smoke" |
| Trapper John, M.D. | Beaumont | Episode: "Love Is a Three-Way Street" |
| A Man Called Sloane | Jonathan Cambro | Episode: "The Venus Microbe" |
| 1980 | Hawaii Five-O | Jack Ellington | Episode: "School for Assassins" |
| Eight Is Enough | Michael Hayes | Episode: "A Matter of Mentors" |
| The Incredible Hulk | Colonel Brad | Episode: "Prometheus: Part II" |
| Disneyland | Colonel Joe Buxley | Episode: "The Ghosts of Buxley Hall" |
| Beyond Westworld | Captain Mike Nicholson | Episode: "Take-Over" |
| The Love Boat | Captain Brad Wells | Episode: "Boomerang/Captain's Triangle/Out of This World" |
| Fantasy Island | Edmond Dumont | Episode: "Crescendo/Three Feathers" |
| 1981 | Dallas | Clint Ogden | Recurring role |
| Hart to Hart | Robert Carney | Episode: "What Becomes a Murder Most?" |
| 1982 | The Fall Guy | Ryker | Episode: "License to Kill" |
| Today's FBI | Dr. London | Episode: "Serpent in the Garden" |
| Bret Maverick | Captain Dawkins | Episode: "The Vulture Also Rises" |
| Matt Houston | Richard Hoyt | Episode: "Joey's Here" |
| Jack Holborn | Trumpet | Miniseries |
| Fantasy Island | Walter Lukas | Episode: "The Magic Camera/Mata Hari/Valerie" |
| Ron Martin | Episode: "Face of Love/Image of Celeste" |
| 1983 | Simon & Simon | Professor Altman | Episode: "Psyched Out" |
| The Love Boat | Joe Costello | Episode: "The Captain's Crush/Out of My Hair/Off-Course Romance" |
| Fantasy Island | Dr. Mark Reed | Episode: "Nurses Night Out" |
| Hotel | Daniel Brunell | Episode: "Designs" |
| 1984 | The A-Team | Lt. Mason Harnett | Episode: "Say It with Bullets" |
| The Master | CIA Head | Episode: "Hostages" |
| Finder of Lost Loves | Galen Smith | Episode: "Maxwell Ltd: Finder of Lose Loves Pilot" |
| Rituals | Carter Robertson | Recurring role |
| 1986 | Blacke's Magic | Douglas Shayne | Episode: "Death Goes to the Movies" |
| Murder, She Wrote | Ned Olson | Episode: "If a Body Meet a Body" |
| 1987 | Hotel | John Granger | Episode: "Glass People" |
| Murder, She Wrote | Inspector Donald Matheney | Episode: "Doom with a View" |
| 1988 | 1st & Ten | Charles | Episode: "The Bulls Own Up" |
| The Golden Girls | Clayton Hollingsworth | 2 Episodes: "Scared Straight" and ”Sister of the Bride” |
| 1989 | 1st & Ten | Medford | Episode: "Duty Calls" |
1989-1992 | Baywatch | Captain Don Thorpe | Recurring role |
| 1991 | Murder, She Wrote | Andrew Gant | Episode: "Family Doctor" |
| 1993 | Jimmy Haynes | Episode: "The Survivor" |
| 1994 | Melrose Place | John Parker | Recurring role |
| 1994-1995 | Grace Under Fire | Travis Taylor | 2 episodes |
| Biography | Narrator | Recurring role |
| 1995 | Burke's Law | Philip D'Arcy | Episode: "Who Killed the Sweet Smell of Success?" |
| 1995-1996 | Campus Cops | Dean Pilkington | Recurring role |
| 1996 | Star Trek: Deep Space Nine | Fullerton | Episode: "Let He Who Is Without Sin..." |
| 1996-2005 | The Great Ships | Narrator | Recurring Role |
| 1998 | Diagnosis: Murder | Sheriff Kelso | Episode: "Dead in the Water" |
| 1999 | Honey, I Shrunk the Kids: The TV Show | William Tecumseh Jennings | 2 episodes |
| 2001 | Fly Past | Narrator | Miniseries |
| 2009 | Cold Case | Glenn Drew '09 | Episode: "The Brush Man" |
| 2011 | Extraordinary Fidelity | Narrator | Documentary |
| Fringe | Dr. Blake West | Episode: "Wallflower" |
| 2012 | Leland Spivey | Episode: "The End of All Things" |
| Leverage | Dr. Everett Udall | Episode: "The Rundown Job" |
| 2015 | The PET Squad Files | Kerry Ling | Episode: "Welcome to F***ing Hollywood" |