| Anna Torv | Olivia Dunham |
| Joshua Jackson | Peter Bishop |
| Lance Reddick | Alternate Phillip Broyles |
| Blair Brown | Nina Sharp
(credit only) |
| Jasika Nicole | Alternate Astrid Farnsworth |
| John Noble | Dr. Walter Bishop /
Walternate |
| Aaron Ashmore | Matthew Rose |
| Shawn Ashmore | Joshua Rose |
| Seth Gabel | Alternate Lincoln Lee |
| Amy Madigan | Marilyn Dunham |
| Holly Elissa | Danielle Rose
(as Holly Dignard) |
| Ryan McDonald | Alternate Brandon Fayette |
| Kirk Acevedo | Alternate Charlie Francis |
| Nate Bell | Rose Son, Age 5
(as Nathan Bell) |
| Chaz Chamberlain | ND Agent |
| Darren Dolynski | Mark Wilner |
| Mig Macario | Agent #1 |
| Peter MacRae | Young Boy |
| Matthew Mandzij | Tech |
| Raf Rogers | Nurse Maude
(as Rafael Pellerin) |
| Lily Pilblad | Ella
(voice) |
| Ricki Prosper | Nurse Alice |
| Nicolas Russo | Rose Son, Age 7 |
| Quelemia Sparrow | Agent #2 |
| Yolanda Jessel | Mother
(as Yolanda Ulmer) |
| Cameron K. Smith | Cab Driver
(uncredited) |