| David Duchovny | ... Agent Fox Mulder |
| Gillian Anderson | ... Agent Dana Scully |
|
| Martin Landau | ... Kurtzweil |
| Blythe Danner | ... Cassidy |
| William B. Davis | ... The Cigarette-Smoking Man |
| John Neville | ... The Well-Manicured Man |
| Mitch Pileggi | ... Assistant Director Walter Skinner |
| Jeffrey DeMunn | ... Bronschweig |
| Terry O'Quinn | ... Michaud |
|
| and |
| Armin Mueller-Stahl | ... Strughold |
|
| Lucas Black | ... Stevie |
| Chris Fennell | ... 2nd Boy |
| Cody Newton | ... 3rd Boy |
| Blake Stokes | ... 4th Boy |
| Dean Haglund | ... Langly (The Lone Gunmen) |
| Bruce Harwood | ... Byers (The Lone Gunmen) |
| Tom Braidwood | ... Frohike (The Lone Gunmen) |
| Don S. Williams | ... Group Elder |
| George Murdock | ... 2nd Elder |
| Michael Shamus Wiles | ... Black-Haired Man |
| Craig Davis | ... Primitive #1 |
| Carrick O'Quinn | ... Primitive #2 |
| Tom Woodruff, Jr. | ... Creature #1 |
| Gregory B. Ballora | ... Creature #2 |
| Ted King | ... FBI Agent on Roof |
| Luis Beckford | ... FBI Agent |
| Steve Rankin | ... Field Agent |
| Gary Grubbs | ... Fire Captain Cooles |
| Steven M. Gagnon | ... Last Agent Out |
| Lawrence Joshua | ... DC Cop |
| Glendon Rich | ... DC Cop #2 |
| Gunther Jensen | ... Security Guard |
| Scott Smith | ... Technician |
| Ian Ruskin | ... Well-Manicured Man's Valet |
| Paul Welterlen | ... Control Room Operator |
| Joel Traywick | ... Young Naval Guard |
| Milton Johns | ... British Valet |
| Paul Tuerpé | ... 1st Paramedic |
| Michael A. Krawic | ... 2nd Paramedic |
| Larry Rippenkroeger | ... Towncar Driver |
| Josh McLaglen | ... Buzz Mihoe |
| Randy Hall | ... Windbreakered Agent |
| T. C. Badalato | ... Fireman |
| Amine Zary | ... Tunisian |
| David W. Paris | ... Pilot |
|
| Puppeteers |
| Alec Gillis | ... Supervising Puppeteer |
| John Lundberg | ... Puppeteer |
| Greg Manion | ... Puppeteer |
| Christine Papalexis | ... Puppeteer |
| Van Snowden | ... Puppeteer |
| N. Brock Winkless IV | ... Puppeteer |
| Anthony Matijevich | ... Puppeteer |
| Jimmy Hart | ... Puppeteer |
