All 166 actors in both ER and The Rookie
166 actors have appeared in both ER and The Rookie, across 475 episodes. The most-credited is Ellen Crawford, Nurse Lydia Wright, Woodward in ER and Shirley in The Rookie.
| Actor | In ER | In The Rookie | Eps | Eps |
|---|---|---|---|---|
| Ellen Crawford | Nurse Lydia Wright, Woodward | Shirley | 114 | 1 |
| Arjay Smith | Brian | James Murray | 1 | 31 |
| Matthew Glave | Dr. Dale Edson | Oscar Hutchinson | 15 | 13 |
| Michael Beach | Al Boulet | Commander Percy West | 19 | 7 |
| Angel Parker | Gibbs | Luna Grey | 2 | 20 |
| Sharif Atkins | Dr. Michael Gallant | Police Officer | 12 | 1 |
| Currie Graham | James | Ben McRee | 1 | 7 |
| Lourdes Benedicto | Rena Trujillo | Imelda Sanchez | 5 | 1 |
| Michelle C. Bonilla | Paramedic Christine Harms | Martina Sanchez | 58 | 1 |
| Harold Perrineau | Isaac Price | Detective Nick Armstrong | 1 | 10 |
| Demetrius Grosse | Officer Newkirk | Detective Kevin Wolfe | 5 | 5 |
| Niecy Nash | Judith Anderson | FBI Trainee Simone Clark | 1 | 4 |
| Gil McKinney | Dr. Paul Grady | Barry Langley | 23 | 1 |
| Julie Ann Emery | Paramedic Niki Lumley | Stacy | 6 | 2 |
| Sarah Shahi | Tara King | Jessica Russo | 1 | 7 |
| Sara Rue | Jane | Nell Forester | 1 | 6 |
| Camille Guaty | Mia | Sandra "La Fiera" De La Cruz | 1 | 5 |
| José Zúñiga | Eduardo Lopez | Nestor Garcia | 2 | 1 |
| Ryan Michelle Bathé | Miss Evelyn | Detective Jennifer Paige | 1 | 2 |
| Kamar de los Reyes | Hernandez, Paramedic | Detective Sergeant Ryan Caradine | 3 | 5 |
| Carlos Gómez | Paramedic Raul Melendez | Detective Desmond | 6 | 1 |
| Maury Sterling | Dr. Nelson | Marcus | 5 | 2 |
| David Krumholtz | Paul Sobriki | Ezra Kane | 3 | 1 |
| Michael B. Silver | Dr. Paul Myers | Special Agent Wyck Byrd | 12 | 1 |
| Marlene Forte | Mrs. Gonzalez | Karla Juarez | 1 | 4 |
| Tamala Reneé Jones | Joanie Robbins | Yvonne Thorsen | 3 | 2 |
| Jane Daly | Diane Armitage | Patrice Evers | 1 | 5 |
| Scott Michael Campbell | EMT Reilly Brown | Julius | 7 | 1 |
| Frances Fisher | Helen Kingsley | Evelyn Nolan | 1 | 2 |
| Jeffrey D. Sams | Dr. Dorsey Watson | Dr. Solomon Lowell | 1 | 3 |
| Josh Stewart | Daniel | Graham Porter | 1 | 1 |
| L. Scott Caldwell | Dr. Rabb | Mabel St. Clair | 2 | 1 |
| Mitch Pileggi | Terry Waters | Rex | 1 | 1 |
| Monique Gabriela Curnen | Nurse Blanca | Rita Sanchez | 1 | 3 |
| Michael Patrick McGill | Detective Ed Bernstein, Security #1, Officer Jeffries | Harvey | 6 | 1 |
| Trevor Morgan | Scott Anspaugh | Spyker | 5 | 1 |
| Gregg Henry | Officer Mark Downey | Judge | 1 | 1 |
| Jason Wiles | Officer Maurice "Bosco" Boscorelli | Jeff Budny | 1 | 1 |
| Kai Lennox | Steve Maldonado | Distressed Man | 1 | 1 |
| Valeri Ross | McGillis | Dr. Rogers | 4 | 1 |
| David Dastmalchian | Young Man | Ray Watkins | 1 | 2 |
| Dohn Norwood | MP, Mr. Persky | Deacon Joe | 2 | 1 |
| Myndy Crist | Valerie Page | Abby | 2 | 1 |
| Raphael Sbarge | Mr. Kirkendall | Jonah Russell | 2 | 1 |
| Tom Wright | Wharton | Colin Hall | 2 | 1 |
| Tim Griffin | Captain John Evans | Aiden Warner | 2 | 2 |
| Gina Hecht | Radiology Tech | Dr. Meg Davidson | 2 | 2 |
| Joe Nieves | Tony Dejesu | Conrad Bataglia | 1 | 1 |
| Jose Pablo Cantillo | Juan Enriquez | Franco DeSantis | 1 | 1 |
| Kyle Davis | Kyle | Ruben's Henchman, Vince Jameson | 1 | 2 |
| Michael Kostroff | Community Theater Director | Rafael | 1 | 1 |
| Shi Ne Nielson | Med Student Sheila | Susan Banker | 4 | 1 |
| John Siciliano | Tobias | Mitch | 2 | 1 |
| Tina Lifford | Evelyn Pratt | Warden Miller | 2 | 1 |
| Veronica Cartwright | Norma Houston | Beatrice O'Malley | 2 | 1 |
| Billy Lush | Benny | Murray | 1 | 1 |
| Eric Nenninger | Psychotic Biting Patient | David | 1 | 1 |
| Greg Serano | EVAC Pilot | T.O. Martinez | 1 | 1 |
| Helen Eigenberg | Renee Weber Stewart | Opal Jesper | 1 | 1 |
| Henri Lubatti | Victor | Drew Heslov | 1 | 1 |
| Jayne Taini | Marge Satterfield | Elderly Woman | 1 | 1 |
| LisaGay Hamilton | Nadine Hopkins | Henry's Doctor | 1 | 1 |
| Patrick Fischler | Chamber Tech | Mr. Karga | 1 | 1 |
| Peter Onorati | Officer Nick Napolitano | Officer Jerry McGrady | 1 | 1 |
| Rebecca Field | Psych Woman | Sarah Murphy | 1 | 1 |
| Taylor Nichols | Mr. Adams | Matt Christian | 1 | 1 |
| Linara Washington | Rena Carlson, Young Woman on Train | Alice Hicks | 2 | 1 |
| Tom Virtue | Pares | Judge Lawrence Hunt | 1 | 2 |
| Freda Foh Shen | Audiologist | Maeve | 3 | 1 |
| Brett Rickaby | Vincent Hales | Rodney Acker | 1 | 1 |
| Chris Conner | Mr. Reinhart | Nicholas Colston | 1 | 1 |
| Drew Powell | Dennis Voltaire | Eric 'Knuckles' Mills | 1 | 1 |
| Hayley McFarland | Candice | Ms. Marcos | 1 | 1 |
| Jon Sklaroff | Bible Guy, Eddie Hainey | Stuart Packer | 2 | 1 |
| Karina Logue | Radio Show Host | Laurie Harris | 1 | 1 |
| Marisol Ramirez | Mrs. Escalante | Paula | 1 | 1 |
| Patricia Belcher | Ward Nurse | Mrs. Crouch | 1 | 1 |
| Rebecca Metz | Waitress | Medical Examiner | 1 | 1 |
| Scott Menville | Beidermeier | Manager | 1 | 1 |
| Thomas Dekker | 4 Year Old Boy | Jeffrey Boyle | 1 | 1 |
| Troy Ruptash | Dave Fern | Max Kegel | 1 | 1 |
| Will Beinbrink | Wick | Christian Batista | 1 | 2 |
| Alexandra Billings | Ms. Mitchell | Sergeant Stella Porter | 1 | 1 |
| Andrew Hawkes | Hagan | Marcus Leonard | 1 | 1 |
| Armin Shimerman | Levine | Judge Paloma | 1 | 1 |
| Arye Gross | Kevin | Professor Meadows | 1 | 1 |
| Bertila Damas | Dr. Debra Wexler | Maria Ochoa | 1 | 1 |
| Dayo Ade | James Rollins | Jonathan Ryland | 1 | 1 |
| Eugene Byrd | James Connor | Tenant #2 | 1 | 1 |
| Jared Padalecki | Paul Harris | Jared Padalecki | 1 | 1 |
| Julanne Chidi Hill | Mother | Meth Addict | 1 | 1 |
| Kari Coleman | Mona | Susan | 1 | 1 |
| Michael Chieffo | Dr. Harris | Homicide Witness | 1 | 1 |
| Michael Reilly Burke | Dick White | Fred Mitchell | 1 | 1 |
| Miguel Pérez | Santiago Escalona | Detective Dave Delgado | 1 | 1 |
| Onahoua Rodriguez | Alma | Estudio Forma Manager | 1 | 1 |
| Page Leong | Gloria, Erin | Daniel's Mother | 3 | 1 |
| Reggie Lee | Christian | Mike Weston | 1 | 1 |
| Andi Chapman | Joanie Albright | Margaret | 2 | 1 |
| Carol Kiernan | Desk Clerk, Doris | Tourist | 2 | 1 |
| Roxanne Hart | Mrs. Kottmeier | Maris Town | 2 | 1 |
| Amanda Carlin | Librarian | Alma | 1 | 1 |
| Brady Smith | Rod | Rico | 1 | 1 |
| Casey Biggs | Mike | Ed Tesca | 1 | 1 |
| David DeLuise | Brad Anderson | Truman | 1 | 1 |
| Federico Dordei | Aldo | Romeo Cabarelli | 1 | 1 |
| Jenn Liu | Rocker Girl | FBI Tech | 1 | 1 |
| Jim Ortlieb | Cook | Judge Stevens | 1 | 1 |
| Nicole Bilderback | Claire | IA Detective | 1 | 1 |
| Robert Clendenin | Anesthesiologist | Dr. Braxton | 1 | 1 |
| Taneka Johnson | Kris | ER Doctor | 2 | 1 |
| Alyson Reed | Ginny | Tenant #1 | 1 | 1 |
| Annie Fitzgerald | Devin Paxon | Diner Manager | 1 | 1 |
| Bob Glouberman | Jeff | Larry Ellis | 1 | 1 |
| Brian Leckner | Lloyd | Airport Officer Holcomb | 1 | 1 |
| Emerson Brooks | Gonzalez | Thomas Forsythe | 1 | 1 |
| Eve Brenner | Wilma | Ruth | 1 | 1 |
| Ivar Brogger | Deposition Attorney | Dean Chatterton | 1 | 1 |
| James MacDonald | Officer Gary McWayne | FBI Academy Instructor | 1 | 1 |
| John Marshall Jones | Mr. Gaither | Mr. Andrews | 1 | 1 |
| Kathe Mazur | Kate Nelson | Lawyer | 1 | 1 |
| Lily Knight | Mary Cochran | Dr. Roberts | 1 | 1 |
| Marlon Young | Paramedic Thomas | Sergeant McAdams | 1 | 1 |
| Nancy Linehan Charles | Glenda Walton | Ghost Lady | 1 | 1 |
| Saxon Trainor | Karen Simms | Mrs. Watkins | 1 | 1 |
| Amanda Wyss | Mrs. Adams | Meredith Russell | 1 | 1 |
| Bonnie Root | Lori | Mrs. Goodwin | 1 | 1 |
| Harvey J. Alperin | Dr. Saunders | Malcolm Walker | 1 | 1 |
| Jamison Yang | Shuang Tseng | Officer Yamada | 1 | 1 |
| Mark Harelik | James | William Bloomfield | 1 | 1 |
| Matthew Jones | Cop | Judge Sinclair | 1 | 1 |
| Molly Baker | Mary Marchak | Lawyer | 1 | 1 |
| Paul Nakauchi | Harvard Candidate | Dr. Kang | 1 | 1 |
| Vanessa Martinez | Tiffany James | Elena | 1 | 1 |
| Alex Solowitz | James / "Mr. Midnight" | Mimic | 1 | 1 |
| David Gianopoulos | John Dean / Bob Halderman | FBI Agent Keegan | 1 | 1 |
| Deidrie Henry | Nichelle Richardson | Dr. Spader | 1 | 1 |
| Mercedes Colon | Detective | Watch Commander | 1 | 1 |
| Rigo Sanchez | Vega | Salvador Arroyo | 1 | 1 |
| Shelley Robertson | Tanya Phillips | Samantha Bennett | 1 | 1 |
| Wayne Péré | Eric Farve | Dez Robinson | 1 | 1 |
| Will Rothhaar | Robert "Bo" Borsalino | Perp | 1 | 1 |
| Alain Uy | Burke | Dahrio Salonga | 1 | 1 |
| Angelo Vacco | Mercy RN | Scared Father | 1 | 1 |
| Jeremy Guskin | Knight | Jorge | 1 | 1 |
| Jose Vasquez | Nat | Miguel | 1 | 1 |
| Judith Moreland | Nurse Terry | Linda Brooks | 1 | 1 |
| Kurt Caceres | Luis Sanchez | Russell | 1 | 1 |
| Michael Dempsey | Mr. Beckwith | Captain Howard Jennings | 1 | 1 |
| Wilmer Calderon | Mickey Stubbs | Ralph Stevens | 1 | 1 |
| Brian McGovern | Rob | Randy Fischer | 1 | 1 |
| Chad E. Donella | Kevin Delaney | Kevin Payne | 1 | 1 |
| Geoffrey Rivas | Haven | Howard Green | 1 | 1 |
| Jon Curry | Karl | Cosgrove | 1 | 1 |
| Monnae Michaell | Mrs. Bell | Mrs. Richards | 1 | 1 |
| Peter James Smith | Mr. Shimahara | Paul | 1 | 1 |
| Terry Woodberry | Cop | Clerk | 1 | 1 |
| Vincent Duvall | Father | Captain Duane Tovar | 1 | 1 |
| Matthew Yang King | Rick | Trent Silver | 1 | 1 |
| David O'Donnell | Bill | Simon Sawyer | 1 | 1 |
| Denzel Whitaker | Hassan | Tasker | 1 | 1 |
| Jay Harik | Seiger | Yuri | 1 | 1 |
| Kelli Dawn Hancock | Tina Kirk | Ronda | 1 | 1 |
| Kevin Fry | Detective Demetras | Donny | 1 | 1 |
| Jeff Corbett | Mike Dodds | Lawrence Calisto | 1 | 1 |
| Time Winters | Emil Savka | Marcus | 1 | 1 |
Cast data from TVmaze, licensed CC BY-SA 4.0.