Filmography85 titles
| Year | Title | Character | Age at release |
|---|---|---|---|
| 2026 | MouseMovie | Mr. Murdaugh | 67 |
| 2025 | This Ordinary ThingMovie | Self (voice) | 66 |
| 2024 | The ExorcismMovie | Father Conor | 65 |
| 2022 | JuliaSeries | Paul Child | 63 |
| 2020 | Stars in the HouseSeries | Self | 61 |
| 2019 | The Lavender ScareMovie | Dr. Franklin E. Kameny (voice) | 60 |
| 2017 | When We RiseSeries | Dr. Jones | 58 |
| 2017 | Wet Hot American Summer: Ten Years LaterSeries | Henry Neumann | 58 |
| 2017 | Julie's GreenroomSeries | David Hyde Pierce | 58 |
| 2016 | Must See TV: An All Star Tribute to James BurrowsMovie | Self | 57 |
| 2015 | Wet Hot American Summer: First Day of CampSeries | Henry Neumann | 56 |
| 2015 | Hurricane of Fun: The Making of Wet HotMovie | Self | 56 |
| 2014 | Late Night with Seth MeyersSeries | Self | 55 |
| 2012 | Vanya and Sonia and Masha and SpikeMovie | Vanya | 53 |
| 2010 | Sondheim! The Birthday ConcertMovie | Self - Host | 51 |
| 2010 | The Perfect HostMovie | Warwick Wilson | 51 |
| 2009 | The Good WifeSeries | Frank Prady | 50 |
| 2009 | Stingray SamMovie | Narrator | 50 |
| 2008 | Monty Python Conquers AmericaMovie | Self | 49 |
| 2007 | The Graham Norton ShowSeries | Self | 48 |
| 2006 | The Megan Mullally ShowSeries | Self - Guest | 47 |
| 2006 | The Amazing Screw-On HeadMovie | Emperor Zombie (voice) | 47 |
| 2006 | World's Greatest Stand Up: Volume OneMovie | self | 47 |
| 2005 | Celebrity MixMovie | Self (archive footage) | 46 |
| 2004 | The Tony Danza ShowSeries | Self | 45 |
| 2004 | The Celebrity ApprenticeSeries | Self | 45 |
| 2004 | HellboyMovie | Abe Sapien (voice) (uncredited) | 45 |
| 2004 | Frasier: Analyzing the LaughterMovie | Niles Crane | 45 |
| 2003 | Down with LoveMovie | Peter MacMannus | 44 |
| 2003 | Gary the RatSeries | — | 44 |
| 2003 | The Shakespeare SessionsMovie | — | 44 |
| 2003 | Behind the Couch: The Making of 'Frasier'Movie | Self | 44 |
| 2002 | Full FrontalMovie | Carl | 43 |
| 2002 | Treasure PlanetMovie | Doctor Doppler (voice) | 43 |
| 2002 | Laud WeinerMovie | Laud Weiner | 43 |
| 2001 | Osmosis JonesMovie | Drix (voice) | 42 |
| 2001 | Wet Hot American SummerMovie | Henry | 42 |
| 2001 | Chain of FoolsMovie | Mr. Kerner | 42 |
| 2001 | On the EdgeMovie | Barney (segment "Happy Birthday") | 42 |
| 2000 | TitusSeries | Jerry October | 41 |
| 2000 | Isn't She GreatMovie | Michael Hastings | 41 |
| 2000 | The Tangerine Bear: Home in Time for Christmas!Movie | Bird (voice) | 41 |
| 1999 | Jackie's Back!Movie | Perry (The Deaf Rehearsal Pianist) | 40 |
| 1999 | The Late Late Show with Craig KilbornSeries | Self - Guest | 40 |
| 1999 | The Mating Habits of the Earthbound HumanMovie | The Narrator | 40 |
| 1999 | The Frasier StoryMovie | Self | 40 |
| 1998 | HerculesSeries | Daedalus (voice) | 39 |
| 1998 | A Bug's LifeMovie | Slim (voice) | 39 |
| 1997 | The ViewSeries | Self | 38 |
| 1996 | Mighty Ducks: The Animated SeriesSeries | Baron Von Lichtenstamp (voice) | 37 |
| 1996 | Star Trek: 30 Years and BeyondMovie | Niles Crane | 37 |
| 1995 | The Outer LimitsSeries | Dr. Jack Henson | 36 |
| 1995 | Caroline in the CitySeries | Jimmy Callahan | 36 |
| 1995 | Happily Ever After: Fairy Tales for Every ChildSeries | Puss (voice) | 36 |
| 1995 | NixonMovie | John Dean | 36 |
| 1995 | The World of James BondMovie | Self | 36 |
| 1995 | The Adventures of HypermanSeries | — | 36 |
| 1994 | WolfMovie | Roy McCallister | 35 |
| 1993 | FrasierSeries | Niles Crane | 34 |
| 1993 | Addams Family ValuesMovie | Delivery Room Doctor | 34 |
| 1993 | Sleepless in SeattleMovie | Dennis Reed | 34 |
| 1993 | Late Show with David LettermanSeries | Self - Guest | 34 |
| 1993 | Late Night with Conan O'BrienSeries | Self - Guest | 34 |
| 1992 | The Tonight Show with Jay LenoSeries | Self | 33 |
| 1992 | The Powers That BeSeries | Theodore Van Horne | 33 |
| 1992 | StorytimeSeries | — | 33 |
| 1991 | The Fisher KingMovie | Lou Rosen | 32 |
| 1991 | Little Man TateMovie | Garth Emmerick | 32 |
| 1990 | Dream OnSeries | Jerry Dorfer | 31 |
| 1989 | The SimpsonsSeries | Cecil Terwilliger (voice) | 30 |
| 1989 | Vampire's KissMovie | Theater Guy | 30 |
| 1988 | LIVE with Kelly and MarkSeries | Self - Guest | 29 |
| 1988 | Crossing DelanceyMovie | Mark | 29 |
| 1988 | Bright Lights, Big CityMovie | Bartender at Fashion Show | 29 |
| 1988 | Rocket GibraltarMovie | Monsieur Henri | 29 |
| 1988 | The Appointments of Dennis JenningsMovie | Businessman | 29 |
| 1988 | KnightwatchSeries | Gibson | 29 |
| 1985 | Spenser: For HireSeries | O'Neill | 26 |
| 1985 | Moving ViolationsMovie | Immigration Officer | 26 |
| 1975 | Saturday Night LiveSeries | Self - Host | 16 |
| 1956 | Tony AwardsSeries | Self - Presenter | — |
| 1952 | TodaySeries | Self | — |
| 1949 | The Emmy AwardsSeries | Self | — |
| 1944 | Golden Globe AwardsSeries | Self - Nominee | — |
| 0 | Vivien & the FloristMovie | John Gielgud | — |