| 2025 | Estamos todos en directo con John Mulaney (serie) | Self - Willy Loman, Weston Playhouse, Weston, VT, 2010 (Pre-Tape Segment) |
| 2024 | Man and Witch: The Dance of a Thousand Steps | The Alchemist |
| 2024 | Man in the Long Black Coat | Sol Fassbinder |
| 2024 | Knuckles (serie) | Chief Pachacamac (voice) |
| 2023 | Camp Hideout | Falco |
| 2023 | Nandor Fodor and the Talking Mongoose | Dr. Harry Price |
| 2022 | Noche de sustos | Alex Windsor |
| 2022 | Tankhouse | Buford |
| 2021 | El bar de las grandes esperanzas | Grandpa Maguire |
| 2021 | Next Stop, Christmas | Ticket Agent/Conductor |
| 2021 | The Center Seat: 55 Years of Star Trek (serie) | Self |
| 2021 | El club de las abejas reina | Arthur Lane |
| 2021 | Hacks (serie) | Larry Arbuckle |
| 2021 | Senior Moment | Sal Spinelli |
| 2021 | Expedición: Regreso al futuro (serie) | Self |
| 2021 | Nadie | David Mansell |
| 2020 | Reunited Apart (serie) | Self |
| 2019 | The Haunted Swordsman | The Black Monk |
| 2019 | The Mandalorian (serie) | Commissioner Helgait |
| 2019 | Dr. Jack & Mr. Nicholson | Self |
| 2018 | Los Conners (serie) | Lou Vitore |
| 2018 | A Million Little Things (serie) | Christopher Lloyd |
| 2018 | ReRUN | George Benson (old) |
| 2018 | Making a Killing | Lloyd Mickey |
| 2018 | La historia de la ciencia ficción (serie) | Self |
| 2018 | A.P. Bio (serie) | Melvin |
| 2017 | Musa | Bernard Rauschen |
| 2017 | The Boat Builder | Abner |
| 2017 | The Sound | Clinton Jones |
| 2016 | Cold Moon | James Redfield |
| 2016 | I am not a serial killer | Mr. Crowley |
| 2015 | Justo a Tiempo para Navidad | Grandpa Bob |
| 2015 | Doc Brown Saves the World | Emmett Brown |
| 2015 | Keith Lemon's Back t'Future Tribute | Self |
| 2015 | Back in Time | Self |
| 2015 | Regreso al presente | — |
| 2015 | 12 monos (serie) | Zalmon Shaw / The Missionary |
| 2015 | 88 | Cyrus |
| 2014 | The One I Wrote For You | Pop |
| 2014 | Más allá del jardín (serie) | The Woodsman (voice) |
| 2014 | Codigo Pirata:Las aventuras de Mickey Matson | Grandpa Jack |
| 2014 | Los signos del apocalipsis | Harry Setag |
| 2014 | Lago de Sangre: El ataque de las lampreas asesinas | Mayor Akerman |
| 2014 | La verdadera historia de la ciencia ficción (serie) | Himself |
| 2014 | Buenas noches (serie) | Self |
| 2013 | El show de Michael J. Fox (serie) | Principal McTavish |
| 2013 | Sid the Science Kid: The Movie | Dr. Bonabodon (voice) |
| 2012 | Anything but Christmas | Harry |
| 2012 | Excuse Me for Living | Lars |
| 2012 | Muertos antes del amanecer | Horus Galloway |
| 2012 | The Narrative of Victor Karloch | Victor Karloch |
| 2012 | Foodfight! | Mr. Clipboard (voice) |
| 2012 | Las Aventuras de Mickey Matson y la conspiración del cabeza de cobre | Grandpa Jack |
| 2012 | Dorothy and the Witches of Oz | The Wizard Of Oz |
| 2012 | La Patrulla Increíble | Professor (voice) |
| 2011 | Adventures of Serial Buddies | Dr. Von Gearheart |
| 2011 | Visiones de un asesinato | Shep |
| 2011 | The Chateau Meroux | Nathan |
| 2011 | Las brujas de Oz (serie) | The Wizard of Oz |
| 2010 | The Haunting Hour: La Serie (serie) | Grandpa Walt Montgomery |
| 2010 | Tales from the Future | Self |
| 2010 | Hope (serie) | Dennis Powers |
| 2010 | Piraña 3D | Mr. Goodman |
| 2010 | Hombres de nieve | The Caretaker |
| 2009 | Live from Studio Five (serie) | Self |
| 2009 | La amenaza de Casandra (serie) | Prof. Daniel Lehman |
| 2009 | Llamada salvaje | 'Grandpa' Bill Hale |
| 2009 | The Macabre World of Lavender Williams | Lester (voice) |
| 2009 | En tiempo de dragones (serie) | Tesselink |
| 2009 | Looking Back to the Future | Self |
| 2008 | Fringe (serie) | Roscoe Joyce |
| 2008 | Camelot: Live from Lincoln Center | King Pellinore |
| 2007 | Flakes | Willie |
| 2007 | Chuck (serie) | Dr. Leo Dreyfus |
| 2007 | Big Bang (serie) | Theodore |
| 2007 | The Alan Titchmarsh Show (serie) | Self |
| 2007 | Head Case (serie) | Self |
| 2006 | Valerie en la escalera | Everett Neely |
| 2006 | Psych (serie) | Martin Kahn |
| 2006 | Looking Back at the Future | Himself |
| 2005 | Maestros del terror (serie) | — |
| 2005 | Here Comes Peter Cottontail: The Movie | Seymour S. Sassafras (voice) |
| 2005 | Stacked (serie) | Harold March |
| 2005 | Numb3rs (serie) | — |
| 2004 | Admissions | Steward Worthy |
| 2004 | Clubhouse (serie) | Lou Russo |
| 2004 | I Dream (serie) | Professor Toone |
| 2004 | The Tony Danza Show (serie) | Self |
| 2004 | Car Crash: The Delorean Story | Himself |
| 2003 | Merry Christmas Space Case | Narrator (voice) |
| 2003 | Navy: Investigación criminal (serie) | Joseph Smith |
| 2003 | Temblores (serie) | Dr. Cletus Poffenberger |
| 2003 | The Haunted Lighthouse | Cap'n Jack |
| 2002 | The Big Time | Doc Powers |
| 2002 | Muérete, mi amor | Bruce |
| 2002 | Interestatal 60 | Ray |
| 2002 | Cyberchase (serie) | Hacker (voice) |
| 2001 | Kids World | Leo |
| 2001 | When Good Ghouls Go Bad | Uncle Fred Walker |
| 2001 | Ley y orden: Acción criminal (serie) | Carmine |
| 2001 | On The Edge | Attorney Bum (segment "Happy Birthday") |
| 2001 | Chasing Destiny | Jet James |
| 2001 | Amar la vida | Dr. Harvey Kelekian |
| 2000 | Ed (serie) | Burt Kiffle |
| 2000 | Convergence | Morley Allen |
| 2000 | Malcolm (serie) | Walter |
| 1999 | El ala oeste de la Casa Blanca (serie) | Professor Lawrence Lessig |
| 1999 | The Emperor's Treasure | Lord Imaru (voice) |
| 1999 | It Came From the Sky | Jarvis Moody |
| 1999 | Unos peques geniales | Heep |
| 1999 | Mi marciano favorito | Uncle Martin |
| 1998 | Las aventuras de Tom Sawyer | Judge Thatcher (voice) |
| 1998 | The Ransom of Red Chief | Sam Howard |
| 1997 | Completely Cuckoo | Self |
| 1997 | Anastasia | Rasputin (voice) |
| 1997 | Un ángel en mi equipo | Al |
| 1997 | Dinner at Fred's | Dad |
| 1997 | Cambio de habitos | Theo Teagarden |
| 1997 | Quicksilver Highway | Aaron Quicksilver |
| 1997 | El rey de la colina (serie) | Smitty (voice) |
| 1996 | Spin City (serie) | Owen Kingston |
| 1996 | Cadillac Ranch | Wood Grimes |
| 1996 | The Right to Remain Silent | Johnny Benjamin |
| 1995 | Cosas que hacer en Denver cuando estás muerto | Pieces |
| 1995 | Deadly Games (serie) | Sebastian Jackal |
| 1995 | Mr. Payback: An Interactive Movie | Ed Jarvis |
| 1995 | Familia de alquiler | Lawrence 'Larry' Kayvey |
| 1994 | The Making of 'The Pagemaster' | Mr. Dewey - Host |
| 1994 | El Guardián de las Palabras | Mr. Dewey |
| 1994 | In Search of Dr. Seuss | Mr. Hunch |
| 1994 | Un campamento en ninguna parte | Dennis Van Welker |
| 1993 | La familia Addams: La tradición continúa | Uncle Fester |
| 1993 | Fallen Angels (serie) | Continental Op |
| 1993 | Daniel, el travieso | Switchblade Sam |
| 1992 | T Bone N Weasel | Weasel |
| 1992 | Dead Ahead: The Exxon Valdez Disaster | Frank Iarossi - Exxon |
| 1991 | La familia Addams | Uncle Fester |
| 1991 | Suburban Commando | Charlie Wilcox |
| 1991 | Regreso al futuro (serie) | Emmett Brown |
| 1991 | Back to the Future: The Ride | Doctor Emmet Brown |
| 1990 | Patoaventuras: La película - El tesoro de la lámpara perdida | Merlock (voice) |
| 1990 | Regreso al futuro III | Doctor Emmett Brown |
| 1990 | A mí que me registren | Bruno Daley |
| 1989 | Los Simpson (serie) | Reverend Jim Ignatowski (voice) |
| 1989 | Regreso al futuro II | Emmett Brown |
| 1989 | Una pandilla de lunáticos | Henry Sikorsky |
| 1988 | Ocho hombres | Bill Burns |
| 1988 | ¿Quién engañó a Roger Rabbit? | Judge Doom |
| 1988 | Ruta 29 | Henry Henry |
| 1987 | Bialy Smok | Jim Martin |
| 1987 | Una auténtica vida de perros | Reggie Shand / Henry Shand |
| 1986 | La aventura más milagrosa jamás contada | Harry |
| 1986 | Cuentos asombrosos | R. Beanes |
| 1985 | El juego de la sospecha (Cluedo) | Professor Plum |
| 1985 | Cuentos asombrosos (serie) | Professor B.O.Beanes |
| 1985 | Regreso al futuro | Emmett Brown |
| 1985 | El halcón callejero (serie) | Anthony Corrido |
| 1984 | The Cowboy and the Ballerina | — |
| 1984 | Las aventuras de Buckaroo Banzai | John Bigboote |
| 1984 | Star Trek III: En busca de Spock | Cmdr. Kruge |
| 1984 | Street Hawk: The Movie | Anthony Corrido |
| 1983 | Soy o no soy | Capt. Schultz |
| 1983 | September Gun | Jack Brian |
| 1982 | Cheers (serie) | Phillip Semenko |
| 1982 | Money on the Side | Sergeant Stampone |
| 1982 | Pilgrim, Farewell | Paul |
| 1981 | Best of the West (serie) | The Calico Kid |
| 1981 | La leyenda del llanero solitario | Maj. Bartholomew 'Butch' Cavendish |
| 1980 | Psicópata | Gilbert |
| 1979 | El campo de cebollas | Jailhouse Lawyer |
| 1979 | The Fantastic Seven | Skip Hartman |
| 1978 | The Word (serie) | Hans Bogardus |
| 1978 | Camino del sur | Towfield |
| 1978 | Taxi (serie) | Reverend Jim 'Iggy' Ignatowski |
| 1978 | Lacy and the Mississippi Queen | Jennings |
| 1977 | Tres Guerreros | — |
| 1975 | Alguien voló sobre el nido del cuco | Max Taber |
| 1975 | Saturday Night Live (serie) | Self - Cameo (uncredited) |
| 1975 | Barney Miller (serie) | Vincent Carew |
