All 103 actors in both Chicago Fire and ER
103 actors have appeared in both Chicago Fire and ER, across 628 episodes. The most-credited is Abraham Benrubi, Russ LaPointe in Chicago Fire and Jerry Markovic in ER.
| Actor | In Chicago Fire | In ER | Eps | Eps |
|---|---|---|---|---|
| Abraham Benrubi | Russ LaPointe | Jerry Markovic | 1 | 137 |
| Amy Morton | Desk Sergeant Trudy Platt | Mrs. Walters | 41 | 1 |
| Christian Stolte | Lieutenant Randy "Mouch" McHolland | Driver | 24 | 1 |
| Mariska Hargitay | Sergeant Olivia Benson | Cynthia Hooper | 1 | 13 |
| Scott Jaeck | Firefighters' Attorney | Dr. Steven Flint | 1 | 12 |
| Eamonn Walker | Deputy Commissioner Wallace Boden | Dr. Stephen Dakarai | 1 | 3 |
| William Smillie | Kevin Hadley | Cassani | 26 | 1 |
| Sarah Shahi | Renee Royce | Tara King | 10 | 1 |
| Shiri Appleby | Clarice Carthage | Dr. Daria Wade, Ms. Murphy | 6 | 10 |
| Mo Gallini | Firefighter Jose Vargas | Guy | 8 | 1 |
| Mena Suvari | Isabella | Laura-Lee Armitage | 7 | 1 |
| Troy Winbush | Detective Pryma | Uniform Cop | 7 | 1 |
| Andrew Rothenberg | Mr. Jameson | Pauly Johnson | 4 | 1 |
| Fredric Lehne | Deputy District Chief Ray Riddle | Bum's Friend | 7 | 1 |
| Barbara Eve Harris | Commander Emma Crowley | Sakina, Mrs. Kendrick | 3 | 3 |
| Carl Weathers | State's Attorney Mark Jefferies | Louie Taylor | 2 | 1 |
| Jacqueline Williams | Officer Becerra | Krieg, TSA Guard | 5 | 2 |
| Meg Thalken | Administrator, Miriam Price | Flight Nurse Dee McManus, Rottman | 2 | 7 |
| Ron Dean | James Whoritsky | Uncle Joey | 3 | 1 |
| Christopher Cousins | Steven Goody | Kyle Kolber | 2 | 1 |
| Jenny O'Hara | Ellie Norwich | Nurse Rhonda Sterling | 1 | 2 |
| Al Vicente | Devin Staples, Deputy Chief Garwood | Luis | 3 | 1 |
| John Hoogenakker | Lieutenant Spellman | Collins | 5 | 1 |
| Kurt Naebig | Grogan, Negotiator | Paramedic | 2 | 2 |
| Page Leong | Helen Chen | Gloria, Erin | 1 | 3 |
| Tom Amandes | Detective Ryan Wheeler | David Gardner | 3 | 1 |
| B.K. Cannon | Darla Thompson | Tammy | 1 | 1 |
| Ilyssa Fradin | Janine Allen, Woman in SUV | Lori | 3 | 1 |
| James Vincent Meredith | Chief Zamos | Speaker | 1 | 1 |
| JoNell Kennedy | Jasmine Lacey | Judy Munder | 1 | 1 |
| Katrina Begin | Olivia | Ginger | 1 | 1 |
| Raphael Sbarge | Larry Herrmann | Mr. Kirkendall | 1 | 2 |
| Howie Johnson | Sgt. Conroy, Lou Krinsky | Zuelke | 3 | 1 |
| Roderick Peeples | Chief Bruce Amshen, Leroy | The Butcher | 3 | 1 |
| Marceline Hugot | Sister Montclair | Bonnie | 2 | 1 |
| Rachel Cerda | FBI Special Agent Julia Cortes, Rose | Mirsa | 2 | 1 |
| Richard Cotovsky | Mick, Pawn Shop Owner | Homeless Man | 2 | 1 |
| Phil Ridarelli | Facilities Roy, Jeff, Mitchell Monroe | Doorman | 3 | 1 |
| Anthony Irons | Jake Williams | Rowdy Man #1 | 2 | 1 |
| Audrey Francis | Margie Cavanaugh | Young Woman | 2 | 1 |
| Carla Gallo | Pam Belfort | Emma Miller | 1 | 1 |
| Coburn Goss | Jed Bell | Stan Griswold | 1 | 1 |
| Jeffrey DeMunn | Construction Worker | Treatment Center Doctor | 1 | 1 |
| Kwame Amoaku | Floyd | Cabbie, Neighbor, Trumpet Player | 1 | 3 |
| Lily Mojekwu | Veronica Harrington | Voice #2 | 2 | 1 |
| Nestor Serrano | Rick Esposito | David Torres, CDC | 1 | 1 |
| Ransford Doherty | Lieutenant LeClerc | Randall James | 1 | 1 |
| Scottie Pippen | Scottie Pippen | Scottie Pippen | 1 | 1 |
| John Judd | Alderman Dearing | Ricci | 1 | 1 |
| Richard Lexsee | Engine Guy, Reid | Firefighter Hudson, Paramedic | 2 | 2 |
| Rusty Schwimmer | Jill | Grollman | 1 | 1 |
| John Gawlik | Officer Banks | Officer Collins | 3 | 1 |
| Alan Wilder | Marvin Watkins | Ottley | 2 | 1 |
| Alicia Lagano | Paramedic Adler | Tracy | 1 | 1 |
| Ariel Felix | Jamael | Student #14 | 1 | 1 |
| Danny McCarthy | Trainer | Firefighter James | 1 | 1 |
| Eddie Shin | Chicago Center Operator | Med Student Stanley Mao | 1 | 2 |
| Gary Kraus | Deputy District Chief Clem Girardi | CJ | 1 | 1 |
| Helen Eigenberg | Ellen Porter | Renee Weber Stewart | 1 | 1 |
| James Waterston | Rich Corbin | Mr. Barney | 1 | 1 |
| Jerry Kernion | Firefighter Mickey Barnes | Bartender | 1 | 1 |
| Karina Logue | Kathy | Radio Show Host | 1 | 1 |
| Madrid St. Angelo | Officer Cordero, Store Manager | Driver | 2 | 1 |
| Robert Knepper | Adrian Gish | Keith Reynolds | 1 | 1 |
| Janelle Snow | Beth Simmons | Doherty | 2 | 1 |
| John Marshall Jones | Supervisory Special Agent Nathan Conway | Mr. Gaither | 1 | 1 |
| Michael Reilly Burke | Chief Jaworski | Dick White | 1 | 1 |
| Wallace Langham | Darren Jackson | Dr. Melvoin | 1 | 1 |
| James MacDonald | Assistant Deputy Commissioner Adam Perry | Officer Gary McWayne | 1 | 1 |
| Jim Cantafio | Bulldozer Driver | Det. Lundberg | 1 | 1 |
| John Lacy | Billy Nicholson | Kevin Poole | 1 | 1 |
| Matt DeCaro | Sergeant Delaney | Soccer Dad | 1 | 1 |
| Kenn E. Head | Tucker | Homeless Man | 1 | 1 |
| Peggy Roeder | Dog-Walking Neighbor | Ruth Huggins | 1 | 1 |
| Robin Weigert | IA Handler Erica Gradishar | Nicole | 1 | 1 |
| Ronnie Gene Blevins | DeLong | Nemo Baker | 1 | 1 |
| Dale Rivera | Rivera | Cabbie | 1 | 1 |
| Rengin Altay | Sara, School Principal | Kitty | 2 | 1 |
| Rich Komenich | Stephanidies | Car Dealer | 1 | 1 |
| Francis Guinan | Fire Commissioner | Police Negotiator | 1 | 1 |
| Karimar Brown | Woman | Nia | 1 | 1 |
| Alma Washington | Miriam | Passenger | 1 | 1 |
| Cedric Young | Deputy District Chief Arend | Leon | 1 | 1 |
| Nicole Bush | Margaret | Mom | 1 | 1 |
| Cerall Duncan | Becca's Mother | Mrs. Price | 1 | 1 |
| Dan Flannery | Callahan | Businessman | 1 | 1 |
| Don Forston | Dr. Drayer | Voice #1 | 1 | 1 |
| Josette DiCarlo | Sandy | Mrs. D'Angelo | 1 | 1 |
| Bernard White | Dr. Woodward | Addict seeking Rapid Detox | 1 | 1 |
| Doug James | Neiman | Foreman | 1 | 1 |
| Joe Dempsey | SUV Driver | Commuter | 1 | 1 |
| Jim Saltouros | Olson | Walt | 1 | 1 |
| Leah Urzendowski | Girlfriend | Barbie | 1 | 1 |
| Joe Krowka | Chief Hale | Grocer | 1 | 1 |
| Kirsten Fitzgerald | Sergeant Halstead | Judy | 1 | 1 |
| Rene L. Moreno | Warehouse Worker | Ed | 1 | 1 |
| Eileen Galindo | Mama Garcia | Heather Tocci | 1 | 1 |
| Lacy Katherine Campbell | Dr. Kessman | Pilarsky | 1 | 1 |
| Nancy Parmalee | Brie McAuley | Vicki Pastroni | 1 | 1 |
| Oscar Daniel Blanco | Latino Kid | Carlos Moore | 1 | 1 |
| Paul Turner | Hooper | Cop | 1 | 1 |
| Richard Pickren | Randolph | Jimmy | 1 | 1 |
| David Girolmo | Chief Grimes | Gaines | 1 | 1 |
Cast data from TVmaze, licensed CC BY-SA 4.0.