All 149 actors in both ER and Mad About You
149 actors have appeared in both ER and Mad About You, across 507 episodes. The most-credited is Leland Orser, Dr. Lucien Dubenko in ER and Professor Gittleson in Mad About You.
| Actor | In ER | In Mad About You | Eps | Eps |
|---|---|---|---|---|
| Leland Orser | Dr. Lucien Dubenko | Professor Gittleson | 61 | 1 |
| Kathleen Wilhoite | Chloe Lewis | Iris | 19 | 2 |
| Gedde Watanabe | Nurse Yosh Takata | The Speech Writer | 58 | 1 |
| Rick Rossovich | Dr. John 'Tag' Taglieri | Sherman Williams | 11 | 1 |
| Perry Anzilotti | Dr. Perry (Anesthesiologist), Ed | Roy Osterback | 22 | 1 |
| Edward Asner | Dr. James McNulty | Zigmund "Ziggy" Klarik | 3 | 3 |
| Mare Winningham | Dr. Amanda Lee | Sarah McKay | 4 | 2 |
| Iqbal Theba | Dr. Zogoiby | The Cabbie | 4 | 1 |
| Jim Piddock | Dr. Earl Whitehead | Hal, The Logic Professor | 1 | 7 |
| Scott Jaeck | Dr. Steven Flint | Pool Player from A.A. | 12 | 1 |
| Eileen Brennan | Betty | Inspector #10 | 2 | 1 |
| Susan Blommaert | Sarah McKenzie | Miss Grundy, Rita | 1 | 2 |
| Paul Dooley | Henry Lewis | Gus Stemple | 4 | 1 |
| Penny Fuller | Mrs. Constantine | Theresa Stemple | 1 | 4 |
| Dean Cameron | Edward | Irwin | 1 | 3 |
| Eric Christmas | Mr. Heath | Bernard | 1 | 1 |
| José Zúñiga | Eduardo Lopez | Arturo | 2 | 2 |
| Mark Tymchyshyn | Mr. Pruitt | Boat Attendant | 1 | 1 |
| Jeff Cahill | Transport Dispatcher Tony Fig | Keanu the Cabbie | 4 | 1 |
| Judyann Elder | Debra Graham | Nurse Lily | 1 | 4 |
| Caitlin Alderton | Skye | Claire | 1 | 2 |
| Kenneth Tigar | Dr. Keinholz | Norman Lark | 2 | 1 |
| Kerri Green | Lynn Parker | Stacey | 1 | 2 |
| Alison Martin | Mrs. Kendrick | Muriel | 1 | 3 |
| Albert Owens | Cardiologist Zane | The Cat | 1 | 1 |
| Alex Rocco | Martin Trudeau | Mark Slotkin | 1 | 1 |
| Anne-Marie Johnson | Sickle Cell Patient | Pre-School Principal | 1 | 1 |
| Debra Mooney | Leila Morgan, Barbara Feingold | Sister Dorothea | 3 | 1 |
| Franklin Cover | Thurnhurst | Yankee Infielder | 1 | 1 |
| John C. Moskoff | Len Weston | Sam | 1 | 1 |
| Nancy Lenehan | Edie Harvell | Dr. Wallach | 1 | 1 |
| Patty Toy | Dr. Leung | Tammy | 1 | 2 |
| Reggie Lee | Christian | Gardner's Assistant | 1 | 1 |
| Robert Costanzo | Pernicious Anemia Man | The Door Guy | 1 | 1 |
| Sheilynn Wactor | Cynthia | STOMP | 1 | 1 |
| Sherman Howard | Mr. Schoenberger | The Executive | 1 | 2 |
| Simon Templeman | Gareth | Martin | 1 | 1 |
| Stacey Travis | Detective Weller | Dawn | 2 | 1 |
| Wayne Wilderson | Dr. Claypool | Bank Executive | 1 | 1 |
| Danny Mora | Guillermo | Racing Fan | 3 | 1 |
| Kevin Michael Richardson | Patrick | The Cable Man | 3 | 1 |
| Bob Glouberman | Jeff | Buchmans' Lawyer, Daniel Kaufman | 1 | 2 |
| Julius Tennon | Mr. Stegman, Uniform Cop | Officer #1 | 2 | 1 |
| Allan Wasserman | Mr. Goldstein | The Lawyer | 1 | 1 |
| Annie Abbott | Mrs. Torledsky | Friendly Woman | 1 | 1 |
| Billye Ree Wallace | Helen 'Silvie' Rubadoux | The Sweet Little Woman | 3 | 1 |
| Carol Ann Susi | Mrs. Clark | Female Passenger | 1 | 1 |
| Cynthia LaMontagne | Paula McKenzie | Melissa Larson | 1 | 1 |
| Estelle Harris | Mrs. Markovic | Barry's Mother | 1 | 1 |
| Ivory Ocean | Mr. Preston | Issac | 1 | 1 |
| Jack Shearer | Hal Grunwald | Manny Gantz | 1 | 1 |
| Jesse D. Goins | Mr. Paige | DiChristophoro' Lawyer | 1 | 1 |
| Judith Hoag | Mrs. Brenner | Doris | 1 | 1 |
| Larry Hankin | Bearded Homeless Guy | Bob the Security Guard | 1 | 1 |
| Lisa Edelstein | Aggie Orton | Lynne Stoddard | 1 | 1 |
| Lisa Waltz | Mrs. Wimbur | Didi | 1 | 1 |
| Marcelo Tubert | Galloway | The Subway Passenger | 3 | 1 |
| Mario Roccuzzo | Mr. Tanzi | Racing Fan | 1 | 1 |
| Peggy Mannix | Mrs. Breeland, Mrs. Styman | The Kissing Woman | 2 | 2 |
| Steve Buscemi | Art Masterson | Howie Ballinger | 1 | 1 |
| E.J. Callahan | Drunk | Celtic Fan, The Gentleman | 1 | 2 |
| Helen Geller | Jean, Mrs. Reynolds | Pirate Maiden | 2 | 1 |
| Pierrino Mascarino | Mr. Clayton | Giuseppe | 1 | 2 |
| Rick Overton | Mr. McNamara | Earl, The Shepherd | 1 | 2 |
| Steven Anderson | Dr. Davitch | Ricky Wrongstag | 2 | 1 |
| Wesley Thompson | Fritz | The Man In The Hospital | 2 | 1 |
| Tom Gallop | Dr. Roger Julian | The Ad Exec | 3 | 1 |
| Al Ruscio | Mr. Dellanova | Uncle Jules | 1 | 1 |
| Alan Wilder | Ottley | Registrar #1 | 1 | 1 |
| Amzie Strickland | Jean Connelly | Woman Customer | 2 | 1 |
| B.J. Ward | Romano's Post-Op Nurse | Announcer, Dr. Cathy | 1 | 2 |
| Brian McNamara | Gil Brenner | Doug | 1 | 1 |
| Fred Pinkard | Mr. Stubey | Yankee Catcher | 1 | 1 |
| Jack Hallett | Jimmy Vogel | The Babyproofer | 1 | 1 |
| Joanna Sanchez | Mrs. Trajillo | Lobbyist #2 | 1 | 1 |
| John C. McDonnell | Rick | The Barfly | 2 | 1 |
| John David Conti | Tony Pipitone | The Bartender | 1 | 1 |
| JoNell Kennedy | Judy Munder | Paul's Flight Attendant | 1 | 1 |
| Julian Stone | Mr. O'Groat | Dr. Griffin | 1 | 1 |
| Kari Coleman | Mona | Molly Norman | 1 | 1 |
| Kyle Sullivan | Nicholas Rosato | Patrick | 1 | 1 |
| Lawrence Mandley | Jackson, Maintenance Man | Leon, Orderly #1 | 2 | 1 |
| Lynn Milgrim | Ms. Crandell | The Maid | 1 | 1 |
| Michael Tomlinson | Dr. Keith Fecteau | Customer | 1 | 1 |
| Miles Marsico | David Bradley | Zack Grundfest | 1 | 1 |
| Nancy Linari | Elizabeth Puro | Louise Ganzenmuller | 1 | 1 |
| Norma Maldonado | Munoz | Consuela the Maid | 2 | 1 |
| Scott Atkinson | Blake | Doug the Handyman | 1 | 1 |
| Sergey Brusilovsky | Adrian, Boris Nadinovitz | Cabbie #1 | 2 | 1 |
| Sofia Milos | Coco | Sarah | 1 | 1 |
| Steven Gilborn | Dr. Randall | Professor Tomassi | 1 | 1 |
| Vince Grant | Jeff Woodman | Bob | 1 | 1 |
| Christian Clemenson | Dr. Kurtag | Jared | 1 | 2 |
| Ajgie Kirkland | Monty | Male Teacher | 1 | 1 |
| Bill Henderson | Charley Barnes | Mets Shortstop | 1 | 1 |
| David Arnott | Clivus | Lester | 1 | 1 |
| Donna Pieroni | Wuss | The Masseuse | 1 | 1 |
| Earl Billings | Ray Jamison | The Security Guard | 1 | 1 |
| Judith Moreland | Nurse Terry | Mrs. Peterson | 1 | 1 |
| Kathy Griffin | Dolores Minky | Brenda | 1 | 1 |
| Kelly Perine | Collins | Man in Line | 1 | 1 |
| Lenny Wolpe | Dr. George Hudson | Monty | 1 | 1 |
| Michael Fairman | Mort Harris | Conductor | 1 | 1 |
| Michael Yama | Epidemiologist | The Dealer | 1 | 1 |
| Toshi Toda | Japanese Businessman 1 | Businessman #2 | 1 | 1 |
| Valente Rodriguez | Mr. Trajillo | Harold the Orderly | 1 | 1 |
| Will Rothhaar | Robert "Bo" Borsalino | Logan | 1 | 1 |
| William Utay | Dr. Lassally | The Maitre'D | 1 | 1 |
| Carole Goldman | Bartender, Doc | The Irate Fan | 2 | 1 |
| Alix Elias | Roxanne | The TV Wife | 1 | 1 |
| Annie Korzen | Mrs. Grunwald | Fritzi | 1 | 1 |
| Christopher Darga | Wilson | Akiba the Cameraman | 1 | 1 |
| Dylan Haggerty | Coach Yazerski | The Young Man | 1 | 1 |
| Harry Hutchinson | Hit and Run Driver | Officer #2 | 1 | 1 |
| Lawrence Adisa | Josh's Cousin | Tony | 1 | 1 |
| Pat Crawford Brown | Mrs. Votey | Neighbor #1 | 1 | 1 |
| Phil Leeds | Husband | Vacky | 1 | 1 |
| Ping Wu | Mr. Cheung | Kim | 1 | 1 |
| Steven M. Porter | Mr. Pularski | Husband | 1 | 1 |
| Cara DeLizia | Andrea Parks | Teenage Mabel | 1 | 2 |
| Andrew J. Ferchland | Ozzie Sheff | Noah | 1 | 1 |
| Dale Godboldo | Hiltzik | Film Student | 1 | 1 |
| Donna Ponterotto | Pearl | The Waitress | 1 | 1 |
| Franc Ross | Naughton | Suit #1 | 1 | 1 |
| Jeanne Mori | Mrs. Bimley | The Campaign Worker | 1 | 1 |
| Len Lesser | Woody Ebbots | Uncle Arnold | 1 | 1 |
| Michael P. Byrne | Bulowski | Crowd Member #2 | 1 | 1 |
| Patricia Place | Mrs. Romero | Annoyed Passenger | 1 | 1 |
| Stan Sellers | James | Neighbor #2 | 1 | 1 |
| David Dunard | Irish Guy | Dan the Cop | 1 | 2 |
| Elizabeth Norment | Mrs. Sandburg | Female Passenger | 1 | 1 |
| Gregg Daniel | Mr. Powell | The Neighbor | 1 | 1 |
| Jann Karam | Cameron | The Donut Lady | 1 | 1 |
| John F. O'Donohue | Mr. Goodwin | Ernest | 1 | 1 |
| Phyllis Lyons | Mrs. Tubbs | Darla | 1 | 1 |
| Cynthia Frost | Mrs. Fruhman | Woman #2 | 1 | 1 |
| Darlene Kardon | Elderly Woman | Svetlana Poszinsky | 1 | 1 |
| Paul Eiding | Kaminski | Herbert | 1 | 1 |
| Armando Molina | Sgt. Pete Jackson | The Delivery Guy | 1 | 1 |
| Frederick Dawson | Bus Driver | Catheter Spokesman | 1 | 1 |
| Jill C. Klein | Mattie Gilman | Aunt Blossom | 1 | 1 |
| Nils Allen Stewart | Kornberg | Six Fingers Malone | 1 | 1 |
| Lance E. Nichols | Detective Barnes | Dr. Eckstein | 2 | 1 |
| Allen Bloomfield | Marty | Pirate | 1 | 1 |
| Bridget Sienna | Hernandez | Mrs. Velasquez | 1 | 1 |
| Nicolette Little | Corinna | Nicolette | 1 | 1 |
| Danny Dayton | Art | Old Man #1 | 1 | 1 |
| Linda Porter | Inga Paulson | The Elderly Patient | 1 | 1 |
| Lillian Hurst | Mrs. Landeta | Phyllis | 1 | 1 |
Cast data from TVmaze, licensed CC BY-SA 4.0.