All 102 actors in both ER and It's Always Sunny in Philadelphia
102 actors have appeared in both ER and It's Always Sunny in Philadelphia, across 518 episodes. The most-credited is David Hornsby, Strauss in ER and Matthew "Rickety Cricket" Mara in It's Always Sunny in Philadelphia.
| Actor | In ER | In It's Always Sunny in Philadelphia | Eps | Eps |
|---|---|---|---|---|
| David Hornsby | Strauss | Matthew "Rickety Cricket" Mara | 1 | 27 |
| Sandy Martin | Mrs. Zarian, Sister Helen | Mrs. Mac | 2 | 18 |
| Lance Barber | Howard | Bill Ponderosa | 1 | 11 |
| Shelly Desai | Cabbie | Hwang | 2 | 3 |
| Stuart McLean | X-Ray Tech, Mike Devore | Another Patron | 12 | 1 |
| Aisha Hinds | Administrator | Welfare Case Worker | 1 | 2 |
| Alejandro Patiño | Best Man | Mr. Juarez | 1 | 2 |
| Atticus Todd | Chris Sakabu | Big Strange Dude | 1 | 2 |
| John Mariano | Leonard | Johnny | 1 | 2 |
| Judy Greer | Tildie Mulligan | Ingrid "Fatty Magoo" Nelson | 1 | 2 |
| Kyle Davis | Kyle | Lil' Kevin | 1 | 2 |
| Alanna Ubach | Terry's Friend | Roxy | 1 | 1 |
| Dean Cameron | Edward | Dave Drisko | 1 | 1 |
| Eddie Mekka | Jenkins | Bobby Thunderson | 1 | 1 |
| Jim O'Heir | McKenna | Doctor | 1 | 1 |
| Kari Coleman | Mona | Margie | 1 | 1 |
| Marlon Young | Paramedic Thomas | Louis | 1 | 1 |
| Patricia Belcher | Ward Nurse | Judge | 1 | 1 |
| Peter Jacobson | Susan's molester | Michael Rotenberg | 1 | 1 |
| Ted Rooney | Dr. Tabash | Curator | 6 | 1 |
| Nasim Pedrad | Nurse Suri | Lucy | 9 | 1 |
| Dona Hardy | Freda, Harriet | Old Woman | 2 | 1 |
| Jack Guzman | Morgan | Young Veteran | 2 | 1 |
| Ken Davitian | Zakar Papazian | Snyder | 2 | 1 |
| Peter MacKenzie | Mr. Pasbalas | Doctor | 1 | 2 |
| Aaron Paul | Doug | Aaron Paul | 1 | 1 |
| Audrey Wasilewski | Officer Wetterling | Nurse | 1 | 1 |
| Bill H. McKenzie | Lee | Rick | 1 | 1 |
| Bonnie Burroughs | Candy | Cop | 1 | 1 |
| Elizabeth Sung | Mrs. May Fong | Female Worker | 1 | 1 |
| Eve Sigall | Genie Weller | Waiter's Mom | 1 | 1 |
| Jack McGee | Rodney McMullen | Detective Lance Girard | 1 | 1 |
| Joanna Sanchez | Mrs. Trajillo | Maria | 1 | 1 |
| John Walcutt | Cancer Specialist | Doctor | 2 | 1 |
| Judith Drake | Greta | Lil' Kevin's Mom | 1 | 1 |
| Keegan-Michael Key | Witkowski | Grant Anderson | 1 | 1 |
| Pat Crawford Brown | Mrs. Votey | Woman - Historical Society | 1 | 1 |
| Sheryl Lee Ralph | Gloria Gallant | Barbara Howard | 2 | 1 |
| Takayo Fischer | Trinnie | Mr. Kim | 1 | 1 |
| Maury Sterling | Dr. Nelson | Man | 5 | 1 |
| Ray Porter | Sam Broder | Gerry | 3 | 1 |
| Eddie Shin | Med Student Stanley Mao | Moderator Mike | 2 | 1 |
| Jerry Hauck | Umpire | Boss Hogg | 1 | 2 |
| Windell D. Middlebrooks | Arnie | Nick | 1 | 2 |
| Cody Kasch | Jason Bender | Cheesefoot | 1 | 1 |
| Eddie Pepitone | Dying Patient | Tony | 1 | 1 |
| Gina Morelli | Mirissa | Hispanic Woman | 1 | 1 |
| Jim Cody Williams | Boudreau | Owner | 1 | 1 |
| John Rosenfeld | FBI Agent Robert Clayton | Morris | 1 | 1 |
| Karl T. Wright | Dr. Norris | Scott | 1 | 1 |
| Kathleen Mary Carthy | Nurse Blake | Female Doctor | 1 | 1 |
| Mercedes Colon | Detective | Council Woman | 1 | 1 |
| P.J. Byrne | Ken the Kiosk Man | Tad | 1 | 1 |
| Robert Blanche | Detective Milne | Detective Jones | 1 | 1 |
| Sam Witwer | Tommy | Muscular Guy | 1 | 1 |
| Tony Rivard | Ernie | Handless Guy | 1 | 1 |
| Darris Love | Hudson, Man in Jail | Worker | 2 | 1 |
| Lawrence Mandley | Jackson, Maintenance Man | Black Dude | 2 | 1 |
| Brian McLaughlin | John Esmond | Kid | 1 | 1 |
| Carter MacIntyre | Wallace | Male Model, Mike | 1 | 2 |
| Courtney Gains | Ronnie | Roach | 1 | 1 |
| Donna Pieroni | Wuss | Martha | 1 | 1 |
| Gary Kraus | CJ | Dad | 1 | 1 |
| Jay Harik | Seiger | Gas Station Owner | 1 | 1 |
| Jeremy Radin | Leonard | Sketchy Nick | 1 | 1 |
| Jose Yenque | Wardell | Ernesto | 1 | 1 |
| Lynette DuPree | Athena | Nurse | 1 | 1 |
| Patrick Thomas O'Brien | Carmichael | Associate | 1 | 1 |
| Phil Abrams | Rodney | Doctor | 1 | 1 |
| Steve Tom | MacPherson | Jameson Taft | 1 | 1 |
| Bill Chott | Glen Ashman | Gary | 1 | 1 |
| Brady Smith | Rod | Tony | 1 | 1 |
| James Stellos | Maitre 'D | Manager | 1 | 1 |
| Jareb Dauplaise | Chris Hawkins | Tom | 1 | 1 |
| Jeff Kober | Stuart | Creepy Guy | 1 | 1 |
| Jordana Capra | OB Attending | Film Society Woman | 1 | 1 |
| Marcus Toji | Binkey | Phil | 1 | 1 |
| Paul Bartholomew | Mr. Burke | Psychic John | 1 | 1 |
| Ryan Michelle Bathé | Miss Evelyn | Woman-Office Worker | 1 | 1 |
| Will Beinbrink | Wick | 1st Man at Art Show | 1 | 1 |
| Bob Rusch | Lillion | Doyle McPoyle | 1 | 1 |
| Chris Hendrie | Capt. Crawford | Detective | 1 | 1 |
| David Douglas | Miller | Customer | 1 | 1 |
| Diane Sellers | Mrs. Garrison | Clerk | 1 | 1 |
| Edward James Gage | Orderly | Phil | 1 | 1 |
| Eric Kaldor | Bachelor #3 | Old Peasant Man | 1 | 1 |
| Matthew Jones | Cop | Customer #1 | 1 | 1 |
| Phil Idrissi | Nail Man | Salesman | 1 | 1 |
| Tom Virtue | Pares | Rink Official | 1 | 1 |
| Yara Martinez | Mia | Kelly | 1 | 1 |
| Amy Higgins | Victoria | Receptionist | 1 | 1 |
| Harvey J. Alperin | Dr. Saunders | Professor 2 | 1 | 1 |
| Kate Mulligan | Riggs | Brenda | 1 | 1 |
| Jon Baggio | Man | Toad Man | 1 | 1 |
| Sonia Jackson | Ruthie Newton | Crack Whore | 1 | 1 |
| Steven Lee Allen | Contractor | Fat Guy | 1 | 1 |
| Brian McGovern | Rob | Tom | 1 | 1 |
| Cleo King | Mrs. Davies | Nurse Wendy | 1 | 1 |
| Jim Ortlieb | Cook | Belka Maier | 1 | 1 |
| Philip Newby | Mike | Nebbish Guy | 1 | 1 |
| Terence Bernie Hines | Felton | Father | 1 | 1 |
| Seth Ayott | Larry | Gunman | 1 | 1 |
← ER × It's Always Sunny in Philadelphia
Cast data from TVmaze, licensed CC BY-SA 4.0.