All 136 actors in both Mad About You and Seinfeld
136 actors have appeared in both Mad About You and Seinfeld, across 356 episodes. The most-credited is Estelle Harris, Barry's Mother in Mad About You and Estelle Constanza in Seinfeld.
| Actor | In Mad About You | In Seinfeld | Eps | Eps |
|---|---|---|---|---|
| Estelle Harris | Barry's Mother | Estelle Constanza | 1 | 29 |
| John O'Hurley | Dr. VonDerphal | J. Peterman | 1 | 21 |
| Len Lesser | Uncle Arnold | Uncle Leo | 1 | 14 |
| Patrick Warburton | Sam | David Puddy | 1 | 10 |
| Spencer Klein | Ryan Devanow | Kid | 6 | 1 |
| Larry Miller | Lou Bonaparte | Doorman | 5 | 1 |
| Ping Wu | Kim | Ping | 1 | 4 |
| Hiram Kasten | Leon | Michael | 1 | 3 |
| Janeane Garofalo | Mabel Buchman | Jeannie Steinman | 2 | 2 |
| Sam Lloyd | Cousin David | Ricky | 2 | 2 |
| Regis Philbin | Regis Philbin | Miss America Pagent Announcer, Regis Philbin | 1 | 2 |
| Tracy Kolis | Ira's Friend | Kelly, Marlene | 1 | 2 |
| Wayne Wilderson | Bank Executive | Walter | 1 | 4 |
| Ana Gasteyer | Yoga Woman | Woman | 1 | 1 |
| Debra Mooney | Sister Dorothea | Mrs. Sweedler | 1 | 1 |
| Eric Christmas | Bernard | Haarwood | 1 | 1 |
| Erick Avari | Dr. Arzupian | Cabbie | 1 | 1 |
| Ernie Sabella | Maurice | Naked Man | 1 | 1 |
| Iqbal Theba | The Cabbie | Cabbie | 1 | 1 |
| John Fleck | Ricky | Attendant | 1 | 1 |
| Kari Coleman | Molly Norman | Allison | 1 | 3 |
| Mark Tymchyshyn | Boat Attendant | Phil Totola | 1 | 1 |
| Melinda McGraw | Cheryl Gendelman | Angela | 1 | 1 |
| Patrick Bristow | Troy, The Clerk | Wig Master | 5 | 1 |
| Stephen Tobolowsky | Principal Hocksacker | Tor Eckman | 1 | 1 |
| Marty Rackham | The Phone Repair Man | Jake Jarmel, Officer #1 | 1 | 4 |
| Darrell Kunitomi | Kim | Lab Technician | 2 | 1 |
| Lisa Edelstein | Lynne Stoddard | Karen | 1 | 2 |
| Lou Cutell | Eddie | Howard Cooperman, MD | 2 | 1 |
| Lawrence Mandley | Leon, Orderly #1 | Larry, Larry the Cook, Manager | 1 | 6 |
| Alison Martin | Muriel | Lucy | 3 | 1 |
| Rick Overton | Earl, The Shepherd | The Drake | 2 | 2 |
| David Dunard | Dan the Cop | Guard, Leader, Security Guard | 2 | 3 |
| Alexandra Bokyun Chun | Gift Wrapping Clerk | Lotus | 1 | 1 |
| Bill Erwin | Yankee Third Baseman | Sid | 1 | 2 |
| Billye Ree Wallace | The Sweet Little Woman | Nana | 1 | 3 |
| Greg Collins | Sergio | Policeman | 1 | 1 |
| Janet Zarish | Saleslady #1 | Rental Car Agent | 1 | 1 |
| Jay Leno | Jay Leno | Jay Leno | 1 | 1 |
| JoNell Kennedy | Paul's Flight Attendant | Secretary | 1 | 1 |
| Larry Hankin | Bob the Security Guard | Tom Pepper (Kramer) | 1 | 2 |
| Liz Georges | The Mother | Pam | 1 | 1 |
| Meagen Fay | Connie | Mrs. Burns | 2 | 1 |
| Michael Fairman | Conductor | Mr. Pensky | 1 | 1 |
| Nancy Lenehan | Dr. Wallach | Volunteer | 1 | 1 |
| Ralph Bruneau | Jim | Roy | 1 | 1 |
| Sherman Howard | The Executive | Roy | 2 | 1 |
| Vic Polizos | The Truck Driver | Tabachnik | 1 | 1 |
| Wendie Malick | Carol | Wendy | 1 | 1 |
| Annie Korzen | Fritzi | Doris, Passenger #2 | 1 | 4 |
| Al Ruscio | Uncle Jules | Manager | 1 | 2 |
| Brad Garrett | Nurse Wadowich | Tony Abado | 1 | 2 |
| Elena Wohl | Ellen | Sandi Robbins (Elaine) | 1 | 2 |
| Fred Pinkard | Yankee Catcher | Newstand Boy, Old Man | 1 | 2 |
| John Michael Higgins | Patrick | Kurt | 2 | 1 |
| Kathy Griffin | Brenda | Sally Weaver | 1 | 2 |
| Monica Allison | Sycophant #2 | Gail, Stewardess | 1 | 2 |
| Richard Portnow | Arthur | Ray | 2 | 1 |
| Allan Wasserman | The Lawyer | Grossbard | 1 | 1 |
| Bridget Sienna | Mrs. Velasquez | Evie | 1 | 1 |
| Carol Ann Susi | Female Passenger | Carrie | 1 | 1 |
| Don McManus | Chris Tofsky | Duncan | 1 | 1 |
| Edie McClurg | Rosie | Mrs. Oliver | 1 | 1 |
| Eric Allan Kramer | Skippy, Orderly #2 | Biker | 1 | 1 |
| Ivory Ocean | Issac | Officer Morgan | 1 | 1 |
| Jack Shearer | Manny Gantz | Mr. Tuttle | 1 | 1 |
| James Lesure | The Maitre'D | Office Worker | 1 | 1 |
| Jesse D. Goins | DiChristophoro' Lawyer | Cop | 1 | 1 |
| Jill C. Klein | Aunt Blossom | Waitress | 1 | 1 |
| Jon Polito | Ralphy | Silvio | 1 | 1 |
| Kelly Perine | Man in Line | Usher | 1 | 1 |
| Megan Mullally | Jane | Betsy | 1 | 1 |
| Perry Anzilotti | Roy Osterback | Usher | 1 | 1 |
| Robert Donley | Scat King | Ben | 1 | 1 |
| Stacey Travis | Dawn | Holly | 1 | 1 |
| Vince Grant | Bob | Hal Kitzmiller | 1 | 1 |
| Wayne Tippit | Manny Gantz | Captain | 1 | 1 |
| Wendle Josepher | The Assistant | Susie | 1 | 1 |
| Bill Saluga | Mr. Fefvil, Racing Fan | Usher | 2 | 1 |
| Fred Stoller | Mischa's Master | First Man in Hockey Audience, Fred Yerkes | 1 | 2 |
| Patrick Cronin | The Postal Worker | Farkus | 1 | 2 |
| Pierrino Mascarino | Giuseppe | Father Hernandez | 2 | 1 |
| Tony Edwards | Man in the Store, The Optician | Business Man | 2 | 1 |
| Alex Trebek | Alex Trebek | Alex Trebek | 1 | 1 |
| Amy Hill | The Police Officer | Kim | 1 | 1 |
| Brian McNamara | Doug | James | 1 | 1 |
| Daryl Keith Roach | The Photographer | Blind Violinist / Cop | 1 | 1 |
| Fred Sanders | Pet Store Owner | John | 1 | 1 |
| Gerry Bednob | Cabbie #2 | Babu's Friend | 1 | 1 |
| Jack Hallett | The Babyproofer | Alan | 1 | 1 |
| Karla Tamburrelli | Waula Lea Astin | Daphne | 1 | 1 |
| Kyle Sullivan | Patrick | Son | 1 | 1 |
| Laura Waterbury | Guest #1 | Casting Director | 1 | 1 |
| Marcus Smythe | The Mellifluous Voice | Dan | 1 | 1 |
| Peggy Mannix | The Kissing Woman | Woman | 2 | 1 |
| Scott Jaeck | Pool Player from A.A. | Officer Vogel | 1 | 2 |
| Stan Sellers | Neighbor #2 | Cop #2, McAdam | 1 | 2 |
| Susan Ilene Johnson | Party Guest #1 | Nurse | 1 | 1 |
| William Utay | The Maitre'D | Dr. Korval | 1 | 1 |
| Ralph Manza | Campanella, Saul | Gepetto | 2 | 1 |
| Dylan Haggerty | The Young Man | Young Man | 1 | 1 |
| Kevin Keckeisen | The Little Boy | Brian | 1 | 1 |
| Marita Geraghty | Velma | Margaret | 1 | 1 |
| Nick Jameson | Bruno Mir | Horst | 1 | 1 |
| Richard Roat | Phillip | Dr. Berg | 1 | 1 |
| Stephen Pearlman | The Ethics Professor | Mr. Goldstein | 1 | 1 |
| Toshi Toda | Businessman #2 | Mr. Tanaka | 1 | 1 |
| Wesley Thompson | The Man In The Hospital | Poker Player #2 | 1 | 1 |
| Allen Bloomfield | Pirate | Polar Bear | 1 | 1 |
| Christopher Darga | Akiba the Cameraman | Driver | 1 | 1 |
| David Fresco | Old Man #2 | Isaac | 1 | 1 |
| Fritzi Burr | Klarik's Customer | Mah-Jongg Lady | 1 | 1 |
| Gedde Watanabe | The Speech Writer | Mr. Oh | 1 | 1 |
| John Capodice | Bill | Vic | 1 | 1 |
| Mailon Rivera | Ray | Cop #1 | 1 | 1 |
| Marcelo Tubert | The Subway Passenger | Father | 1 | 1 |
| Steven Hack | Maynard the Editor | Walker #1 | 1 | 1 |
| Bernard Hocke | The Tatoo Artist | Guy in Diner | 1 | 1 |
| Daniel Hagen | Skip | Rick | 1 | 1 |
| Darlene Kardon | Svetlana Poszinsky | Mrs. Lupchek | 1 | 1 |
| John Gegenhuber | Dr. Ben | Resident | 1 | 1 |
| Leon W. Grant | Jeff | Counterperson | 1 | 1 |
| Patricia Place | Annoyed Passenger | Wife | 1 | 1 |
| Tom Gallop | The Ad Exec | Alan | 1 | 1 |
| Al Roker | Al Roker | Al Roker | 1 | 1 |
| Danny Breen | Narrator #2 | Guy with Glasses | 1 | 1 |
| Jann Karam | The Donut Lady | Sandi | 1 | 1 |
| John F. O'Donohue | Ernest | Gus | 1 | 1 |
| Maria Stanton | Jamie's Flight Attendant | Woman in Diner | 1 | 1 |
| Susan Leslie | Bobby's Sister | Nurse | 1 | 1 |
| Carol Rosenthal | Deejay | Ticket Clerk #1 | 1 | 1 |
| Murray Rubin | Al Birnbaum | Rubin | 1 | 1 |
| Rudolph Giuliani | Rudy Giuliani | Rudolph Giuliani | 1 | 1 |
| Armando Molina | The Delivery Guy | Amigo | 1 | 1 |
| Jack Esformes | The Crew Guy | Mike | 1 | 1 |
| Golde Starger | Woman #1 | Bldg 'A' | 1 | 1 |
Cast data from TVmaze, licensed CC BY-SA 4.0.