Editing Jason Alexander (section)

===Television===
{| class="wikitable sortable"
|-
! Year
! Title
! Role
! Notes
! class=unsortable|Ref.
|-
| 1981
| ''[[Senior Trip (1981 film)|Senior Trip]]''
| Pete
| Television film
|
|-
| 1984–1985
| ''[[E/R]]''
| Harold Stickley
| 15 episodes
|
|-
| 1986
| ''[[Rockabye (1986 film)|Rockabye]]''
| Lt. Ernest Foy
| Television film
|
|-
| 1987
| ''[[Everything's Relative (1987 TV series)|Everything's Relative]]''
| Julian Beeby
| 10 episodes
|
|-
| 1988
| ''[[Newhart]]''
| Ramming
| Episode: "Courtin' Disaster"
|
|-
| 1989–1998
| ''[[Seinfeld]]''
| [[George Costanza]]
| Main role; 178 episodes
|
|-
| 1992–1993
| ''[[Dinosaurs (TV series)|Dinosaurs]]''
| Various voices
| Recurring role; 7 episodes
| 
|-
| 1993
| ''[[Dream On (TV series)|Dream On]]''
| Randall Townsend
| Episode: "Oral Sex, Lies and Videotape"
|
|-
|1993–1998
| ''[[Saturday Night Live]]''
| Himself
| 2 episodes
|
|-
| 1994–1997
| ''[[Duckman]]''
| Eric Duckman (voice)
| Main role; 70 episodes
|
|-
| 1994, 1998
| ''[[The Larry Sanders Show]]''
| Himself
| 2 episodes
|
|-
| 1994
| ''[[Aladdin (animated TV series)|Aladdin]]''
| Abis Mal (voice)
| Recurring role; 14 episodes
|
|-
| rowspan="2" | 1995
| ''[[Bye Bye Birdie (1995 film)|Bye Bye Birdie]]''
| Albert Peterson
| Television film
|
|-
| ''[[47th Primetime Emmy Awards]]''
| Himself (co-host)
| Television special
|
|-
| rowspan="3" | 1996
| ''[[Muppets Tonight]]''
| Himself
| Episode: "Jason Alexander"
|
|-
| ''[[The Nanny]]''
| Jack
| Episode: "The Tart with Heart"
|
|-
| ''[[Sesame Street]]''
| Himself
| Episode 3557
|
|-
| rowspan="2" | 1997
| ''[[Remember WENN]]''
| Alan Ballinger
| Episode: "Nothing Up My Sleeve"
|
|-
| ''[[Cinderella (1997 film)|Cinderella]]''
| Lionel
| Television film
|
|-
| 1998–1999
| ''[[Hercules (1998 TV series)|Hercules]]''
| [[Poseidon]] (voice)
| Recurring role; 7 episodes
|
|-
| rowspan="3" | 1999
| ''Jingle Bells''
| Elf
| Voice; Television film
|
|-
| ''Ultimate Trek: Star Trek's Greatest Moments''
| Captain [[James T. Kirk]]
|Television special
|
|-
| ''[[Star Trek: Voyager]]''
| Kurros
| Episode: "[[Think Tank (Star Trek: Voyager)|Think Tank]]"
|
|-
| 1999–2000
| ''[[Dilbert (TV series)|Dilbert]]''
| [[Catbert]] (voice)
| Main role; 9 episodes
|
|-
| 2001, 2009
| ''[[Curb Your Enthusiasm]]''
| Himself
| Recurring role; 5 episodes
|
|-
| rowspan="3" | 2001
| ''[[Friends]]''
| Earl
| Episode: "The One Where Rosita Dies"
|
|-
| ''[[Bob Patterson (TV series)|Bob Patterson]]''
| Bob Patterson
| Main role; 10 episodes; also executive producer
|
|-
| ''[[The Legend of Tarzan (TV series)|The Legend of Tarzan]]''
| Zutho
| Voice, episode: "Tarzan and the Face from the Past"
|
|-
| rowspan="4" | 2002
| ''[[Son of the Beach]]''
| Tex Finklestein
| Episode: "Penetration Island"
|
|-
| ''[[House of Mouse]]''
| Hugo
| Voice; Episode: "Donald Wants to Fly"
|
|-
| ''[[The Twilight Zone (2002 TV series)|The Twilight Zone]]''
| [[Personifications of death|Death]]
| Episode: "One Night at Mercy"
|
|-
| ''[[The Man Who Saved Christmas]]''
| [[A.C. Gilbert]]
| Television film
|
|-
| 2003
| ''[[Malcolm in the Middle]]''
| Leonard
| Episode: "Future Malcolm"
|
|-
| 2004–2005
| ''[[Listen Up (TV series)|Listen Up]]''
| Tony Kleinman
| Main role; also producer
|
|-
| 2004
| ''[[A Christmas Carol (2004 film)|A Christmas Carol]]''
| [[Jacob Marley]]
| Television film
|
|-
| 2005
| ''[[Monk (TV series)|Monk]]''
| Marty Eels
| Episode: "[[Mr. Monk and the Other Detective]]"
|
|-
| rowspan="2" | 2006
| ''[[Odd Job Jack]]''
| Don
| Voice; episode: "Twenty-One You're Dead"
|
|-
| ''[[Campus Ladies]]''
| Professor
| Episode: "A Very Special Episode"
|
|-
| 2006–2007
| ''[[Everybody Hates Chris]]''
| Principal Edwards
| 2 episodes
|
|-
| rowspan="2" | 2008
| ''[[The New Adventures of Old Christine]]''
| Dr. Palmer
| Episode: "One and a Half Men"
|
|-
| ''[[Criminal Minds]]''
| Prof. Rothchild
| Episode: "Masterpiece"
|
|-
| 2009
| ''[[Meteor (miniseries)|Meteor]]''
| Dr. Chetwyn
| 2 episodes
|
|-
| rowspan="2" | 2010–2013
| ''[[Fish Hooks]]''
| Mr. Nibbles
| Voice; 3 episodes
| <ref name="btva" />
|-
| ''[[The Cleveland Show]]''
| Saul Friedman
| Voice; 2 episodes
|
|-
| 2010, 2023
| ''[[American Dad!]]''
| Sal / Mr. Orlando
| Voice; 2 episodes
|
|-
| rowspan="5" | 2011
| ''[[Glenn Martin, DDS]]''
| Brandon
| Voice; episode: "GlenHog Day"
|
|-
| ''[[Franklin & Bash]]''
| Carter Lang
| Episode: "Big Fish"
|
|-
| ''[[Harry's Law]]''
| Richard Cross
| Episode: "Bad to Worse"
|
|-
| ''[[China, IL]]''
| Harold
| Voice; 2 episodes
|
|-
| ''[[A Fairly Odd Movie: Grow Up, Timmy Turner!]]''
| Human Cosmo
| Television film
|
|-
| 2011–2012
| ''[[Dora the Explorer (TV series)|Dora the Explorer]]''
| Owl
| Voice; 3 episodes
| <ref name="btva" />
|-
| rowspan="2" | 2012
| ''[[Two and a Half Men]]''
| Dr. Goodman
| Episode: "The Straw in My Donut Hole"
|
|-
| ''Clipaholics''
| Narrator
| Voice; main role
|
|-
| 2013
| ''[[Community (TV series)|Community]]''
| Mountain Man
| Episode: "[[Intro to Felt Surrogacy]]"
|
|-
| rowspan="4" | 2014
| ''[[Comedians in Cars Getting Coffee]]''
| George Costanza
| Episode: "George Costanza: The Over-Cheer"
|
|-
| ''[[Kirstie (TV series)|Kirstie]]''
| Stanford Temple
| Episode: "Maddie's Agent"
|
|-
| ''[[Comedy Bang! Bang! (TV series)|Comedy Bang! Bang!]]''
| Inspector Gantlet
| Episode: "[[Jenna Fischer]] Wears a Floral Blouse & Black Heels"
|
|- 
| ''[[How Murray Saved Christmas]]''
| Doc Holiday
| Voice; Television film
|
|-
| 2014–2017
| ''[[The Tom and Jerry Show (2014 TV series)|The Tom and Jerry Show]]''
| Rick (voice)
| Voice; 11 episodes
| <ref name="btva" />
|-
| rowspan="4" | 2015
| ''[[Big Time in Hollywood, FL]]''
| Himself
| Episode: "The Hand That Feeds"
|
|-
| ''[[Penn Zero: Part-Time Hero]]''
| Coach Wallace
| Voice; episode: "Ultrahyperball"
| <ref name="btva" />
|-
| ''[[Drunk History]]''
| [[William M. Tweed|William "Boss" Tweed]]
| Episode: "Journalism"
|
|-
| ''League of Legends with Videogamedunkey''
| Himself
| Episode: "Brucer Zin Zow"
|
|-
| rowspan="2" | 2015–2016
| ''[[The Grinder (TV series)|The Grinder]]''
| Cliff Bemis
| 4 episodes
|
|-
| ''[[TripTank]]''
|Various voices
|6 episodes
|<ref name="btva" />
|-
| 2016
| ''The Mark Lembeck Technique''
| Mark Lembeck
| Pilot
|
|-
| rowspan="3" | 2017
| ''[[Animals.]]''
| Algae
| Voice, episode: "Rats"
|<ref name="btva" />
|-
| ''[[The Simpsons]]''
| Bourbon Verlander
| Voice; episode: "[[The Caper Chase]]"
|
|-
| ''[[Hit the Road (TV series)|Hit the Road]]''
| Ken Swallow
| Main role; also co-creator, writer and executive producer
|
|-
| 2017–2018
| ''Kody Kapow''
| Goji
| Voice; recurring role
|
|-
| 2017, 2019
| ''[[Robot Chicken]]''
| [[Krampus]]
| Voice; 2 episodes
|
|-
| 2018–2022
| ''[[Young Sheldon]]''
| Gene Lundy
| 5 episodes
|
|-
| 2018
| ''Broadway: Beyond the Golden Age''
| Himself
| Documentary
|
|-
| 2018–2019
| ''[[The Orville]]''
| Olix
| 2 episodes
|
|-
| rowspan="4" | 2019
| ''The Bug Diaries''
| Cicada
| Voice; episode: "Worm's New Digs"
|
|-
| ''Richard Lovely''
| Mr. Mouse
| Voice; Pilot
|
|-
| ''[[Pinky Malinky]]''
| Mayor Hop
| Voice; recurring role
| <ref name="btva" />
|-
| ''[[Mad About You]]''
| Himself
| Episode: "Real Estate for Beginners"
|
|-
| 2019–present
| ''[[Harley Quinn (TV series)|Harley Quinn]]''
| [[Sy Borgman]]
| Voice, 13 episodes
| <ref name="btva" />
|-
| 2019–2022
| ''[[The Marvelous Mrs. Maisel]]''
| Asher Friedman
| 4 episodes
|
|-
| rowspan="2" | 2021
| ''[[The Conners]]''
| Pastor Phil
| 2 episodes
|
|-
| ''[[The Problem with Jon Stewart]]''
|[[Jeff Bezos]]
|Episode: "Working-Class Economy"
|
|-
| 2022
| ''[[Out of Office]]''
| Eliza's Dad
| Television film
|
|- 
| 2022–2024
| ''[[Star Trek: Prodigy]]''
| Doctor Noum
| Voice; 23 episodes
|
|-
| 2023
| ''[[History of the World, Part II]]''
| Maurice Cheeks
| Episode: "VI"
|
|-
| rowspan="2" | 2024
| ''[[Rock Paper Scissors (TV series)|Rock, Paper, Scissors]]''
| Jonathan Fartjoke
| Voice; Episode: "Potato/The Fart Joke Debate"
| 
|-
| ''[[Y llegaron de noche]]''
| [[Carl Laemmle]]
| 4 episodes
|
|}