Actors in both ER and The X-Files
335 actors have appeared in both ER and The X-Files, across 549 episodes. The most-credited is Abraham Benrubi, Jerry Markovic in ER and Big Mike in The X-Files.
| Actor | In ER | In The X-Files | Eps | Eps |
|---|---|---|---|---|
| Abraham Benrubi | Jerry Markovic | Big Mike | 137 | 1 |
| John Aylward | Dr. Donald Anspaugh | Dr. John Rietz | 74 | 1 |
| Mitch Pileggi | Terry Waters | Assistant Director Walter Skinner | 1 | 70 |
| Leland Orser | Dr. Lucien Dubenko | Jason Ludwig | 61 | 1 |
| Paul McCrane | Dr. Robert Romano | Leonard Betts | 30 | 1 |
| CCH Pounder | Dr. Angela Hicks | Agent Lucy Kazdin | 24 | 1 |
| Donal Logue | Flight Nurse Chuck Martin | Agent Tom Colton | 11 | 1 |
| Sam Anderson | Dr. Jack Kayson | U.S. Attorney Leamus | 19 | 1 |
| Penny Johnson Jerald | Nurse Practitioner Lynette Evans | Dr. Hellura Lyle | 9 | 1 |
| Edward Asner | Dr. James McNulty | Maurice | 3 | 1 |
| Ed Lauter | Fire Captain Dannaker | Colonel Marcus Aurelius Belt | 6 | 1 |
| Michael B. Silver | Dr. Paul Myers | Howard Grodin | 12 | 2 |
| Bradley Whitford | Sean O'Brien | Dr. Daniel Trepkos | 2 | 1 |
| Garret Dillahunt | Steve Curtis | Edward Skur | 5 | 1 |
| Vernée Watson | April Wilson | Nurse Whitney Edwards | 2 | 1 |
| Brendan Patrick Connor | Paramedic Reidy | Sheriff Mac Stenzler | 13 | 1 |
| Matthew Glave | Dr. Dale Edson | FBI Prosecutor Kalembrenner | 15 | 2 |
| Aaron Paul | Doug | Winky | 1 | 1 |
| Arye Gross | Kevin | Dr. Puvogel | 1 | 1 |
| Brent Hinkley | Fred Hopper | Brother Andrew | 1 | 1 |
Cast data from TVmaze, licensed CC BY-SA 4.0.