| David Duchovny | Fox Mulder |
| Gillian Anderson | Dana Scully |
| William B. Davis | Smoking Man |
| Chris Owens | Jeffrey Spender |
| Mitch Pileggi | Walter Skinner |
| Mimi Rogers | Diana Fowley |
| Jeff Gulka | Gibson Andrew Praise |
| James Pickens Jr. | Alvin D. Kersh |
| Christopher Neiman | First Carpool Man |
| Kim Robillard | Homer |
| Arthur Taxier | Assistant Director P. Bart |
| Alan Henry Brown | Second Carpool Man |
| Scott Eberlein | Black Haired Man |
| Wendie Malick | Assistant Director J. Maslin |
| Don S. Williams | 1st Elder |
| George Murdock | 2nd Elder |
| Rick Millikan | Sandy |
| Wayne Thomas Yorke | 1st Workman |
| Wayne Alexander | A.D. Arnold |
| Ralph Meyering Jr. | Surgeon |
| Benito Martinez | Orderly |
| Dean Chambers | Power Plant Supervisor
(uncredited) |
| Hardia Madden | FBI Agent
(uncredited) |
| Cazimir Milostan | Firefighter
(uncredited) |