| Anna Torv | Olivia Dunham /
Alternate Olivia Dunham |
| Joshua Jackson | Peter Bishop |
| Lance Reddick | Phillip Broyles /
Alternate Phillip Broyles |
| Blair Brown | Nina Sharp |
| Jasika Nicole | Astrid Farnsworth /
Alternate Astrid Farnsworth |
| John Noble | Dr. Walter Bishop /
Walternate |
| Orla Brady | Alternate Elizabeth Bishop |
| David Call | Nick Lane |
| Seth Gabel | Alternate Lincoln Lee |
| Ari Graynor | Rachel |
| Pascale Hutton | Sally Clark |
| Omar Metwally | James Heath |
| Ryan McDonald | Brandon Fayette |
| Lily Pilblad | Ella |
| Philip Winchester | Frank Stanton |
| Kirk Acevedo | Alternate Charlie Francis |
| Leonard Nimoy | Dr. William Bell |
| Colin Banner | Bus Driver |
| Michael Patrick Denis | Witness /
Jogger
(as Michael Denis) |
| Heather Doerksen | Major Warner |
| Erin Lacourciere | Dying Woman |
| Mig Macario | Tech Tucker |
| Diana Pavlovská | Nurse
(as Diana Pavlovska) |
| Pablo Silveira | Pedestrian |
| Simon Raymond | Fringe Division Tech
(uncredited) |