All 67 actors in both ER and Veronica Mars
67 actors have appeared in both ER and Veronica Mars, across 403 episodes. The most-credited is Michael Muhney, Colin Prentice in ER and Sheriff Don Lamb in Veronica Mars.
| Actor | In ER | In Veronica Mars | Eps | Eps |
|---|---|---|---|---|
| Michael Muhney | Colin Prentice | Sheriff Don Lamb | 1 | 18 |
| Erica Gimpel | Adele Newman | Alicia Fennel | 19 | 8 |
| Christopher B. Duncan | Matthew Graham | Clarence Wiedman | 1 | 8 |
| Cress Williams | Officer Reggie Moore | Nathan Woods | 14 | 4 |
| Mary McDonnell | Eleanor Carter | Jane | 5 | 1 |
| James Molina | Santiago Tabajas | Thumper | 1 | 8 |
| Marcello Thedford | Leon | Super Huge Deputy | 7 | 2 |
| Alex Solowitz | James / "Mr. Midnight" | Tyler Carr | 1 | 4 |
| Onahoua Rodriguez | Alma | Claudia | 1 | 4 |
| Jeffrey D. Sams | Dr. Dorsey Watson | Terrence Cook | 1 | 5 |
| Kyla Pratt | Lily | Georgia | 1 | 1 |
| Linda Castro | Guerrero | Mrs. Murphy | 1 | 9 |
| Christian Clemenson | Dr. Kurtag | Abel Koontz | 1 | 4 |
| Michelle Wolff | Firefighter Rillo | Female Deputy | 1 | 2 |
| Jessica Chastain | Dahlia Taslitz | Sarah Williams | 1 | 1 |
| Megalyn Echikunwoke | Terry Welch | Rain | 1 | 1 |
| Kari Coleman | Mona | Deborah Hauser | 1 | 3 |
| François Chau | Neuro Resident | Hu | 2 | 1 |
| Alanna Ubach | Terry's Friend | Silvia | 1 | 1 |
| Annie Campbell | Joanna | Molly Fitzpatrick | 1 | 3 |
| Michael Kostroff | Community Theater Director | Mr. Pope | 1 | 3 |
| Katie Mitchell | Shelley | Rose Manning | 2 | 2 |
| Bruce Nozick | Craig Simon | Sam Bloom | 2 | 1 |
| Zachery Ty Bryan | Upsilon Psi Lambda Frat Brother | Caz Truman | 1 | 2 |
| Seraina Jacqueline | Berta | Inga | 1 | 4 |
| Aaron Paul | Doug | Eddie Laroche | 1 | 1 |
| Eve Gordon | Mrs. Nugent | Emily Williams | 1 | 1 |
| Mark L. Young | Evan Hayes | Jimmy | 1 | 1 |
| Martin Yu | Jimmy | Mr. Wu | 1 | 3 |
| Adam Scott | David Kerstetter | Mr. Rooks | 1 | 1 |
| Marco Rodríguez | Agent Serena | El Despiadado | 1 | 1 |
| Rachel Roth | Angie Dwyer | Wanda Varner | 1 | 1 |
| Nat McCormick | Pharm Guy | Ted | 1 | 2 |
| Bobby Edner | Zack | Justin Smith | 1 | 1 |
| Carlie Westerman | Jessica Brower | Lauren Sinclair | 1 | 1 |
| Cynthia LaMontagne | Paula McKenzie | Catherine Lenova | 1 | 1 |
| Erin Chambers | Brooke Sawyer | Amelia DeLongpre | 1 | 1 |
| Michael Hyatt | Yvonne Devilliere | Woman's Studies Professor | 1 | 1 |
| Reginald Ballard | Police Officer | Dice | 1 | 1 |
| Sam Sarpong | Antwan | Dime Bag | 1 | 1 |
| Wallace Langham | Dr. Melvoin | Courthouse Clerk | 1 | 1 |
| Charles Duckworth | Mikey | Kelvin Moore | 1 | 1 |
| David Barrera | Felix Hernandez | Carlos Oliveres | 1 | 1 |
| Ivonne Coll | Grandmother | Knitting Grandmother | 1 | 1 |
| Matthew Carey | David | Hans | 1 | 1 |
| Megan Henning | Katie Milner | Sabrina Fuller | 1 | 1 |
| Wilmer Calderon | Mickey Stubbs | Chardo Navarro | 1 | 1 |
| John Ciccolini | Gary Jones | Mechanic | 1 | 1 |
| Marty Ryan | Brant | Bernie | 2 | 1 |
| Gary Carlos Cervantes | Cop | Spaniel Man | 1 | 1 |
| Jerry Zatarain Jr. | Manny Salazar | Pan Wrestler | 1 | 1 |
| Norma Maldonado | Munoz | Maria | 2 | 1 |
| Kate McNeil | Mrs. Pendry | Betina Casablancas | 1 | 1 |
| Chris Babers | Avery Campbell | Jack | 1 | 1 |
| Julie Pop | Hannah, Mary Gitlitz | Patty Wilson | 2 | 1 |
| Paityn James | Leanne | Arriana | 1 | 1 |
| Bridget Hoffman | Mrs. Bradley | Ellen Sinclair | 1 | 1 |
| Daniel Bess | Marshall | Cole | 1 | 1 |
| Terrylene | Gwen's Mother | Mary Mooney | 1 | 1 |
| Ursula Whittaker | Gloria | Single Mother Waitress | 1 | 1 |
| Brian McGovern | Rob | Dr. Bernard Mitchell | 1 | 1 |
| Kip Martin | Rogan | Gordon | 1 | 1 |
| John Maynard | Flasher | Ned Applegate | 1 | 1 |
| Butch Klein | Wynn | Andrew | 1 | 1 |
| Nelson Mashita | Kazuo | James "Jim" Cho | 1 | 1 |
| Tom McCafferty | Worker #1 | Fireman Bill | 1 | 1 |
| Michael Albala | County Anesthesiologist | Executive Type | 1 | 1 |
Cast data from TVmaze, licensed CC BY-SA 4.0.