| — | Untitled Lani Pixels Project | Grandpa (voice) |
| 2025 | Nobody 2 | David Mansell |
| — | Meteor | Prof. Daniel Lehman |
| — | Amazing Stories: The Movie I | Professor (archive footage) |
| — | The Movers | |
| 2024 | Knuckles | Chief Pachacamac (voice) |
| 2024 | Autosufficienza | Dennis Walcott |
| 2024 | Man and Witch: The Dance of a Thousand Steps | The Alchemist |
| 2024 | Guns & Moses | Sol Fassbinder |
| 2023 | STILL - La storia di Michael J. Fox | Dr. Emmet L. Brown (archive footage) (uncredited) |
| 2023 | Nandor Fodor and the Talking Mongoose | Dr. Harry Price |
| 2023 | Un campeggio in fuga | Falco |
| 2022 | Spirit Halloween: The Movie | Alex Windsor |
| 2022 | Tankhouse | Buford |
| 2022 | Who Done It: The Clue Documentary | Self (archive footage) |
| 2021 | Io sono nessuno | David Mansell |
| 2021 | Il bar delle grandi speranze - The Tender Bar | Grandpa Maguire |
| 2021 | DeLorean: Ritorno al futuro | Self |
| 2021 | Prossima fermata: Natale | Ticket Agent/Conductor |
| 2021 | Queen Bees - Emozioni senza età | Arthur Lane |
| 2021 | Senior Moment | Sal Spinelli |
| 2021 | The Center Seat: 55 Years of Star Trek | Self |
| 2021 | King Lear | King Lear |
| 2020 | Reunited Apart | Self |
| 2020 | Stars in the House | Self |
| 2019 | The Mandalorian | Commissioner Helgait |
| 2019 | Dr. Jack & Mr. Nicholson | Self |
| 2019 | The Haunted Swordsman | The Black Monk |
| 2019 | That Guy... Who Was In That Thing 3: Trek Stars | Self |
| 2018 | A.P. Bio | Melvin |
| 2018 | Un milione di piccole cose | Christopher Lloyd |
| 2018 | The Conners | Lou Vitore |
| 2018 | Un viaggio stupefacente | Stanley |
| 2018 | James Cameron - Viaggio nella fantascienza | Self |
| 2018 | Making a Killing | Lloyd Mickey |
| 2018 | ReRUN | George Benson (old) |
| 2017 | Insospettabili sospetti | Milton Kupchak |
| 2017 | La settima musa | Bernard Rauschen |
| 2017 | The Sound | Clinton Jones |
| 2016 | I Am Not a Serial Killer | Mr. Crowley |
| 2016 | For the Love of Spock | Commander Kruge (archive footage) |
| 2016 | Donald Trump's The Art of the Deal: The Movie | Doc Brown |
| 2016 | Cold Moon | James Redfield |
| 2016 | 50 Years of Star Trek | Self |
| 2016 | Must See TV: An All Star Tribute to James Burrows | Self |
| 2015 | 12 Monkeys | The Missionary |
| 2015 | 12 Monkeys | The Missionary (uncredited) |
| 2015 | 12 Monkeys | Zalmon Shaw / The Missionary |
| 2015 | Back in Time | Self |
| 2015 | Appena in tempo per Natale | Grandpa Bob |
| 2015 | 88 | Cyrus |
| 2015 | Ritorno al futuro - 30 anni dopo | |
| 2015 | Doc Brown Saves the World | Emmett Brown |
| 2015 | The Boat Builder | Abner |
| 2015 | Keith Lemon's Back t'Future Tribute | Self |
| 2014 | Un milione di modi per morire nel West | Doc Brown |
| 2014 | Sin City - Una donna per cui uccidere | Kroenig |
| 2014 | Over the Garden Wall - Avventura nella foresta dei misteri | The Woodsman (voice) |
| 2014 | Zodiac: il segno dell'apocalisse | Harry Setag |
| 2014 | Blood Lake - L'attacco delle lamprede killer | Mayor Akerman |
| 2014 | The Real History of Science Fiction | Himself |
| 2014 | Le avventure di Mickey Matson - Il codice dei pirati | Grandpa Jack |
| 2014 | The One I Wrote for You | Pop |
| 2014 | Buenas noches | Self |
| 2013 | The Michael J. Fox Show | Principal McTavish |
| 2013 | Sid the Science Kid: The Movie | Dr. Bonabodon (voice) |
| 2012 | Piranha 3DD | Mr. Goodman |
| 2012 | Foodfight! | Mr. Clipboard (voice) |
| 2012 | Dead Before Dawn | Horus Galloway |
| 2012 | Mickey Matson e la macchina alchemica | Grandpa Jack |
| 2012 | The Oogieloves in The Big Balloon Adventure | Lero Sombrero |
| 2012 | Freedom Force | Professor (voice) |
| 2012 | Le streghe di Oz | The Wizard Of Oz |
| 2012 | Excuse Me for Living | Lars |
| 2012 | Last Call | Pete |
| 2012 | Anything but Christmas | Harry |
| 2012 | The Narrative of Victor Karloch | Victor Karloch |
| 2012 | Cadaver | Cadaver |
| 2012 | Say It Ain't Solo | Himself |
| 2011 | Amore e matrimonio | Dr. George |
| 2011 | Chateau Meroux - Il vino della vita | Nathan |
| 2011 | Le streghe di Oz | The Wizard of Oz |
| 2011 | InSight | Shep |
| 2011 | Il était une fois… Vol au dessus d'un nid de coucou | |
| 2011 | Adventures of Serial Buddies | Dr. Von Gearheart |
| 2010 | Piranha 3D | Mr. Goodman |
| 2010 | R. L. Stine's The Haunting Hour | Grandpa Walt Montgomery |
| 2010 | Il Guinness dei pupazzi di neve | The Caretaker |
| 2010 | Tales from the Future | Self |
| 2009 | Supercuccioli a Natale | Stan Cruge |
| 2009 | Jack and the Beanstalk | Headmaster |
| 2009 | Meteor - Distruzione finale | Prof. Daniel Lehman |
| 2009 | Il richiamo della foresta | 'Grandpa' Bill Hale |
| 2009 | I Cavalieri di Bloodsteel | Tesselink |
| 2009 | Live from Studio Five | Self |
| 2009 | Looking Back to the Future | Self |
| 2009 | The Macabre World of Lavender Williams | Lester (voice) |
| 2008 | Fringe | Roscoe Joyce |
| 2008 | Le avventure del topino Despereaux | Hovis (voice) |
| 2008 | Fly Me to the Moon | Amos (voice) |
| 2008 | Camelot: Live from Lincoln Center | King Pellinore |
| 2007 | The Big Bang Theory | Theodore |
| 2007 | Chuck | Dr. Leo Dreyfus |
| 2007 | Flakes | Willie |
| 2007 | Head Case | Self |
| 2007 | The Alan Titchmarsh Show | Self |
| 2006 | Psych | Martin Kahn |
| 2006 | Valerie on the Stairs | Everett Neely |
| 2006 | A Perfect Day | Michael |
| 2006 | Looking Back at the Future | Himself |
| 2005 | Numb3rs | |
| 2005 | Masters of Horror | |
| 2005 | Bad Girls | Mr. Chauncey |
| 2005 | Stacked - Una pupa in libreria | Harold March |
| 2005 | Arthur Hailey's Detective | Anderson in Launderette |
| 2005 | Here Comes Peter Cottontail: The Movie | Seymour S. Sassafras (voice) |
| 2005 | VM Show Vol. 2 | Dr. Emmett Brown (archive footage) (uncredited) |
| 2004 | The Tony Danza Show | Self |
| 2004 | Admissions | Steward Worthy |
| 2004 | Car Crash: The Delorean Story | Himself |
| 2004 | I Dream | Professor Toone |
| 2004 | Clubhouse | Lou Russo |
| 2003 | NCIS - Unità anticrimine | Joseph Smith |
| 2003 | Tremors | Dr. Cletus Poffenberger |
| 2003 | Merry Christmas Space Case | Narrator (voice) |
| 2003 | The Haunted Lighthouse | Cap'n Jack |
| 2002 | Interstate 60 | Ray |
| 2002 | Hey Arnold! Il film | Coroner (voice) |
| 2002 | Cyberchase | Hacker (voice) |
| 2002 | Wish You Were Dead | Bruce |
| 2002 | The Big Time | Doc Powers |
| 2001 | Law & Order: Criminal Intent | Carmine |
| 2001 | La forza della mente | Dr. Harvey Kelekian |
| 2001 | Fantasmi alla riscossa | Uncle Fred Walker |
| 2001 | On The Edge | Attorney Bum (segment "Happy Birthday") |
| 2001 | Kids World | Leo |
| 2001 | Chasing Destiny | Jet James |
| 2001 | Space Case | Narrator (voice) |
| 2000 | Malcolm | Walter |
| 2000 | Ed | Burt Kiffle |
| 2000 | Convergence | Morley Allen |
| 1999 | Man on the Moon | Self (uncredited) |
| 1999 | West Wing - Tutti gli uomini del Presidente | Professor Lawrence Lessig |
| 1999 | Un genio in pannolino | Heep |
| 1999 | Alice nel paese delle meraviglie | White Knight |
| 1999 | Martin il marziano | Uncle Martin |
| 1999 | Piovuto dal cielo | Jarvis Moody |
| 1999 | The Emperor's Treasure | Lord Imaru (voice) |
| 1998 | Una bionda naturale | Ernst |
| 1998 | The Animated Adventures of Tom Sawyer | Judge Thatcher (voice) |
| 1998 | Il piccolo capo indiano | Sam Howard |
| 1997 | Anastasia | Rasputin (voice) |
| 1997 | King of the Hill | Smitty (voice) |
| 1997 | Quicksilver Highway | Aaron Quicksilver |
| 1997 | Angeli alla meta | Al |
| 1997 | Dinner at Fred's | Dad |
| 1997 | Changing Habits | Theo Teagarden |
| 1997 | Completely Cuckoo | Himself |
| 1996 | Spin City | Owen Kingston |
| 1996 | Spin City | Owen Kingston (archive footage) |
| 1996 | The Right to Remain Silent | Johnny Benjamin |
| 1996 | Cadillac Ranch | Wood Grimes |
| 1995 | Cosa fare a Denver quando sei morto | Pieces |
| 1995 | Bambini a noleggio | Lawrence 'Larry' Kayvey |
| 1995 | Mr. Payback: An Interactive Movie | Ed Jarvis |
| 1995 | Deadly Games | Jordan Kenneth Lloyd |
| 1994 | Pagemaster - L'avventura meravigliosa | Mr. Dewey |
| 1994 | Angels | Al the Angel |
| 1994 | Vacanze a modo nostro | Dennis Van Welker |
| 1994 | Benvenuti a Radioland | Zoltan |
| 1994 | In Search of Dr. Seuss | Mr. Hunch |
| 1994 | The Making of 'The Pagemaster' | Mr. Dewey - Host |
| 1993 | La famiglia Addams 2 | Uncle Fester Addams |
| 1993 | Dennis la minaccia | Switchblade Sam |
| 1993 | Un pezzo da 20 | Jimmy |
| 1993 | Fallen Angels | Continental Op |
| 1992 | Dead Ahead: The Exxon Valdez Disaster | Frank Iarossi - Exxon |
| 1992 | Libertà di reato | Weasel |
| 1991 | La famiglia Addams | Uncle Fester |
| 1991 | Cose dell'altro mondo | Charlie Wilcox |
| 1991 | Ritorno al futuro - La serie animata | Emmett Brown |
| 1990 | Ritorno al futuro - Parte III | Emmett Brown |
| 1990 | Zio Paperone alla ricerca della lampada perduta | Merlock (voice) |
| 1990 | Perché proprio a me? | Bruno Daley |
| 1990 | The Secrets of the 'Back to the Future' Trilogy | Dr. Emmett Brown (archive footage) |
| 1990 | The Earth Day Special | Dr. Emmett L. Brown |
| 1989 | Ritorno al futuro - Parte II | Emmett Brown |
| 1989 | I Simpson | Reverend Jim Ignatowski (voice) |
| 1989 | 4 pazzi in libertà | Henry Sikorsky |
| 1988 | Chi ha incastrato Roger Rabbit | Judge Doom |
| 1988 | Otto uomini fuori | Bill Burns |
| 1988 | Mille pezzi di un delirio | Henry Henry |
| 1988 | Roger Rabbit and the Secrets of Toon Town | Self |
| 1987 | Bobo, vita da cani | Reggie Shand / Henry Shand |
| 1987 | Legend of the White Horse | Jim Martin |
| 1986 | Amazing Stories | R. Beanes |
| 1986 | Miracles | Harry |
| 1985 | Ritorno al futuro | Emmett Brown |
| 1985 | Signori, il delitto è servito | Professor Plum |
| 1985 | Storie Incredibili - Amazing Stories | Professor B.O.Beanes |
| 1985 | Street Hawk - Il falco della strada | Anthony Corrido |
| 1984 | Star Trek III - Alla ricerca di Spock | Cmdr. Kruge |
| 1984 | Le avventure di Buckaroo Banzai nella quarta dimensione | John Bigboote |
| 1984 | Non toccate le ragazze | Coach Hindenberg |
| 1984 | Street Hawk: The Movie | Anthony Corrido |
| 1984 | The Cowboy and the Ballerina | |
| 1983 | Mister mamma | Larry |
| 1983 | Essere o non essere | Capt. Schultz |
| 1983 | September Gun | Jack Brian |
| 1982 | Cin Cin | Phillip Semenko |
| 1982 | National Lampoon's Movie Madness | Samuel Starkman ("Municipalians") |
| 1982 | Money on the Side | Sergeant Stampone |
| 1982 | Pilgrim, Farewell | Paul |
| 1981 | Il postino suona sempre due volte | The Salesman |
| 1981 | La leggenda di Lone Ranger | Maj. Bartholomew 'Butch' Cavendish |
| 1981 | Best of the West | The Calico Kid |
| 1980 | Schizoid | Gilbert |
| 1980 | The Black Marble | Arnold's Collector |
| 1980 | Semi-Tough | |
| 1979 | Il campo di cipolle | Jailhouse Lawyer |
| 1979 | The Lady in Red | Frognose |
| 1979 | Butch and Sundance: The Early Days | Bill Carver |
| 1979 | The Fantastic Seven | Skip Hartman |
| 1978 | Taxi | Reverend Jim Ignatowski |
| 1978 | Taxi | Reverend Jim 'Iggy' Ignatowski |
| 1978 | Verso il sud | Towfield |
| 1978 | The Word | Hans Bogardus |
| 1978 | Lacy and the Mississippi Queen | Jennings |
| 1977 | Un altro uomo, un'altra donna | Jesse James (uncredited) |
| 1977 | Three Warriors | |
| 1975 | Qualcuno volò sul nido del cuculo | Max Taber |
| 1975 | Saturday Night Live | Self - Cameo (uncredited) |
| 1975 | Barney Miller | Arnold Scully |
| 1975 | Barney Miller | Vincent Carew |
| 1956 | Tony Awards | Self - Performer (uncredited) |
