| Movie | 2003 | Bad Santa | Bob Chipeska | |
| Movie | 1988 | Tricks of the Trade | Donald Todsen (uncredited) | |
| Movie | 1973 | The Stone Killer | Hart | |
| Movie | 1998 | Shadow of Doubt | Steven Mayer | |
| Movie | 1991 | The Summer My Father Grew Up | Paul | |
| Movie | 1998 | I Woke Up Early the Day I Died | Robert Forrest | |
| Movie | 2000 | Panic | Josh | |
| Movie | 1990 | Problem Child | Ben | |
| Movie | 1992 | Stay Tuned | Roy Knable | |
| Movie | 1998 | Montana | Dr. Wexler | |
| Movie | 1994 | North | Ward Nelson | |
| Movie | 1998 | Bride of Chucky | Chief Warren Kincaid | |
| Movie | 1981 | They All Laughed | Charles Rutledge | |
| Movie | 1980 | Wholly Moses | Satan (The Devil) | |
| Movie | 1980 | John Ritter: Being of Sound Mind and Body | Self / Various | |
| Movie | 1989 | Skin Deep | Zach | |
| Movie | 1996 | Sling Blade | Vaughan Cunningham | |
| Movie | 1992 | Noises Off... | Garry Lejeune / Roger Tramplemain | |
| Movie | 1982 | The Flight of Dragons | Peter Dickinson (voice) | |
| Movie | 1991 | Problem Child 2 | Ben Healy | |
| Movie | 1972 | The Other | Rider | |
| Movie | 1986 | A Smoky Mountain Christmas | Judge Harold Benton (uncredited) | |
| Movie | 1997 | A Gun, a Car, a Blonde | Duncan the Bartender | |
| Movie | 1980 | Hero at Large | Steve Nichols | |
| Movie | 1987 | Real Men | Bob Wilson | |
| Movie | 1999 | It Came from the Sky | Donald Bridges | |
| Movie | 2002 | Tadpole | Stanley Grubman | |
| Movie | 1979 | Americathon | President Chet Roosevelt | |
| Movie | 2004 | Clifford's Really Big Movie | Clifford the Big Red Dog (voice) | |
| Movie | 2002 | Man of the Year | Bill | |
| Movie | 1996 | Harry Anderson: The Tricks of His Trade | Self | |
| Movie | 1995 | The Colony | Rick Knowlton | |
| Movie | 1984 | All Star Party for Lucille Ball | Self | |
| Movie | 2000 | Terror Tract | Bob Carter | |
| Movie | 2000 | TripFall | Tom Williams | |
| Movie | 1976 | Nickelodeon | Franklin Frank | |
| Movie | 1998 | Chance of a Lifetime | Tom Maguire | |
| Movie | 2003 | Manhood | Eli | |
| Movie | 1993 | Heartbeat | Bill Grant | |
| Movie | 1982 | The Fantastic Miss Piggy Show | Self | |
| Movie | 1999 | Lethal Vows | David Farris | |
| Movie | 1999 | Holy Joe | Joe Cass | |
| Movie | 1998 | Loss of Faith | Bruce Simon Barker | |
| Movie | 1996 | Mercenary | Jonas Ambler | |
| Movie | 1973 | The Lie | Bauer | |
| Movie | 1987 | Prison for Children | David Royce | |
| Movie | 1979 | Echoes of the Sixties: A Musical Trip | Self - Host | |
| Movie | 1986 | Unnatural Causes | Frank Coleman | |
| Movie | 2001 | Nuncrackers | Narrator | |
| Movie | 1980 | The Comeback Kid | Bubba Newman | |
| Movie | 1987 | The Last Fling | Phillip Reed | |
| Movie | 1975 | The Prisoner of Second Avenue | Elevator Passenger (uncredited) | |
| Movie | 1997 | A Child's Wish | Ed Chandler | |
| Movie | 1990 | The Dreamer of Oz | L. Frank Baum | |
| Movie | 2003 | Time Machine: When Cowboys Were King | Self | |
| Movie | 1996 | Sex, Censorship and the Silver Screen | Quote Reader | |
| Movie | 1971 | Scandalous John | Wendell | |
| Movie | 1972 | Evil Roy Slade | Priest (uncredited) | |
| Movie | 1985 | Letting Go | Alex | |
| Movie | 1978 | Leave Yesterday Behind | Paul Stallings | |
| Movie | 1997 | Sink Or Swim | Hank | |
| Movie | 2006 | Stanley's Dinosaur Round-Up | Great Uncle Stew (voice) | |
| Movie | 1971 | The Barefoot Executive | Roger | |
| Movie | 1996 | Unforgivable | Paul Hegstrom | |
| Movie | 1995 | Gramps | Clarke MacGruder | |
| Movie | 2003 | The Golden Girls: Lifetime Intimate Portrait Series | Narrator (voice) | |
| Movie | 1978 | Ringo | Marty Flesh | |
| Movie | 1997 | Nowhere | Moses Helper | |
| Movie | 1988 | Mickey's 60th Birthday | Dudley Goode | |
| Movie | 2000 | Lost in the Pershing Point Hotel | Christian Therapist | |
| Movie | 1989 | My Brother's Wife | Barney | |
| Movie | 1978 | The Goldie Hawn Special | Self | |
| Movie | 1984 | Love Thy Neighbor | Danny Loeb | |
| Movie | 1982 | In Love with an Older Woman | Robert | |
| Movie | 1984 | Strong Kids, Safe Kids | Himself | |
| Movie | 1992 | The Martin & Lewis Story: The Last Great Comedy Team | Self | |
| Movie | 1992 | The Making of High Noon | Self | |
| Movie | 1982 | Pray TV | Tom McPherson | |
| Movie | 1998 | Dead Husbands | Dr. Carter Elston | |
| Movie | 1983 | Sunset Limousine | Alan O'Black | |
| Movie | 1978 | How to Survive the '70s and Maybe Even Bump Into Happiness | Self | |
| Movie | 1984 | Donald Duck's 50th Birthday | Self | |
| Movie | 1978 | Robin Williams: Off the Wall | Self | |
| Movie | 2005 | Mr. Thornton Goes to Hollywood | Self (archive footage) | |
| Movie | 1991 | The Real Story of O Christmas Tree | Piney (voice) | |
| Movie | 1993 | The Only Way Out | Jeremy Carlisle | |
| Movie | 1975 | The Night That Panicked America | Walter Wingate | |
| Movie | 1996 | For Hope | Date #5 (uncredited) | |
| Movie | 1987 | Happy 100th Birthday, Hollywood | Self | |
| TV Show | 1986 | Life with Lucy | John Ritter | 1 |
| TV Show | 1999 | Batman Beyond | Dr. David Wheeler (voice) | 1 |
| TV Show | 1972 | M*A*S*H | Private Carter | 1 |
| TV Show | 1984 | Muppet Babies | | 1 |
| TV Show | 1972 | The Rookies | | 1 |
| TV Show | 1984 | Three's a Crowd | Jack Tripper | 22 |
| TV Show | 1997 | Ally McBeal | George Madison | 2 |
| TV Show | 1975 | Starsky & Hutch | Tom Cole | 1 |
| TV Show | 1977 | The Love Boat | Dale Riley | 1 |
| TV Show | 1994 | Touched by an Angel | Mike O'Conner | 1 |
| TV Show | 1997 | King of the Hill | Eugene Grandy (voice) | 4 |
| TV Show | 1968 | Hawaii Five-O | Ryan Moore | 1 |
| TV Show | 1984 | The Cosby Show | Ray Evans | 1 |
| TV Show | 1972 | The Bob Newhart Show | Dave | 1 |
| TV Show | 1997 | The View | Self | 2 |
| TV Show | 1972 | The Streets of San Francisco | John 'Johnny' Steiner | 1 |
| TV Show | 1990 | Wings | Stuart Davenport | 1 |
| TV Show | 1999 | Law & Order: Special Victims Unit | Dr. Richard Manning | 1 |
| TV Show | 1992 | Hearts Afire | John Hartman | 54 |
| TV Show | 1967 | Mannix | Cliff Elgin | 1 |
| TV Show | 1979 | The Ropers | | 1 |
| TV Show | 1995 | NewsRadio | Frank Westford | 1 |
| TV Show | 1977 | Three's Company | Jack Tripper | 171 |
| TV Show | 1973 | Kojak | Kenny Soames | 1 |
| TV Show | 1969 | Medical Center | Ronnie | 1 |
| TV Show | 1999 | The Early Show | Self | 1 |
| TV Show | 1996 | E! True Hollywood Story | | 4 |
| TV Show | 2002 | 8 Simple Rules | Paul Hennessy | 31 |
| TV Show | 2001 | Scrubs | Sam Dorian | 1 |
| TV Show | 1993 | Late Night with Conan O'Brien | Self - Guest | 1 |
| TV Show | 1994 | Chicago Hope | | 1 |
| TV Show | 1975 | Doc | | 1 |
| TV Show | 2000 | Clifford the Big Red Dog | | 0 |
| TV Show | 1993 | Intimate Portrait | Self - Interviewee | 1 |
| TV Show | 1987 | Hooperman | Detective Harry Hooperman | 42 |
| TV Show | 1999 | Family Law | Father Andrews | 1 |
| TV Show | 2002 | Wednesday 9:30 (8:30 Central) | | 1 |
| TV Show | 1993 | Dave's World | John Ritter | 3 |
| TV Show | 2002 | Breaking News | | 1 |
| TV Show | 1992 | Fish Police | Inspector Gil (voice) | 6 |
| TV Show | 1982 | Nature | Narrator (voice) | 1 |
| TV Show | 1990 | It | Ben Hanscom | 2 |
| TV Show | 1975 | The Bob Crane Show | | 1 |
| TV Show | 2003 | TV Land Awards: A Celebration of Classic TV | | 1 |
| TV Show | 1983 | Life's Most Embarrassing Moments | Self - Host | 1 |
| TV Show | 1998 | Felicity | Mr. Andrew Covington | 7 |
| TV Show | 1992 | The Larry Sanders Show | John Ritter | 1 |
| TV Show | 1993 | Intimate Portrait | Self - Narrator (voice) | 1 |
| TV Show | 2021 | Superstar | Self (archive footage) | 1 |
| TV Show | 1961 | The Mike Douglas Show | Self - Co-Host | 2 |
| TV Show | 1950 | The Bob Hope Show | Self | 1 |
| TV Show | 2000 | Clifford the Big Red Dog | Clifford (voice) | 130 |
| TV Show | 1961 | The Mike Douglas Show | Self | 3 |
| TV Show | 1968 | Hawaii Five-O | Mike Welles | 1 |
| TV Show | 1988 | LIVE with Kelly and Mark | | 1 |
| TV Show | 1992 | Martin & Lewis: Their Golden Age of Comedy | Self | 3 |
| TV Show | 1997 | Over the Top | Justin | 1 |
| TV Show | 2015 | Behind Closed Doors with Natalie Morales | Himself (archive footage) | 1 |
| TV Show | 1994 | Touched by an Angel | Sheriff Tom McKinsley | 1 |
| TV Show | 1974 | Petrocelli | John Oleson | 1 |
| TV Show | 1981 | Entertainment Tonight | Self | 1 |
| TV Show | 2000 | TV Funhouse | Narrator (voice) | 1 |
| TV Show | 1997 | Buffy the Vampire Slayer | Ted Buchanan | 1 |
| TV Show | 1972 | The Waltons | Rev. Matthew Fordwick | 17 |
| TV Show | 1989 | Anything But Love | Patrick Serreau | 5 |
| TV Show | 1997 | Veronica's Closet | Tim Margolin | 1 |
| TV Show | 1944 | Golden Globe Awards | Self - Nominee | 1 |
| TV Show | 1971 | Great Performances | Richard | 1 |
| TV Show | 1944 | Golden Globe Awards | Self | 2 |
| TV Show | 1977 | The Love Boat | Ben Cummins | 2 |
| TV Show | 1974 | Rhoda | Vince Mazuma | 1 |
| TV Show | 1974 | Rhoda | Jerry Blocker | 1 |
| TV Show | 1973 | Barnaby Jones | Joe Rockwell | 1 |
| TV Show | 1971 | Owen Marshall: Counselor at Law | Greg | 1 |
| TV Show | 1970 | The Mary Tyler Moore Show | Reverend Chatfield | 1 |
| TV Show | 1970 | Dan August | Coley Smith | 1 |
| TV Show | 1962 | The Tonight Show Starring Johnny Carson | Self | 9 |
| TV Show | 1962 | The Merv Griffin Show | Self | 1 |
| TV Show | 1974 | Dinah! | Self | 1 |
