| Name | Character | Episodes |
|---|---|---|
| Mireille Enos | Marissa Wiegler | 22 |
| Esmé Creed-Miles | Hanna | 22 |
| Dermot Mulroney | John Carmichael | 14 |
| Joel Kinnaman | Erik Heller | 11 |
| Noah Taylor | Dr. Roland Kunek | 8 |
| Noof Ousellam | Turner | 8 |
| Áine Rose Daly | Trainee 242 / Sandy Phillips | 8 |
| Anthony Welsh | Leo Garner | 8 |
| Yasmin Monet Prince | Clara Mahan | 8 |
| Ray Liotta | Gordon Evans | 6 |
| Khalid Abdalla | Jerome Sawyer | 6 |
| Mia Jenkins | Danielle Marks | 6 |
| Katie Clarkson-Hill | Joanne McCoy | 6 |
| Adam Bessa | Abbas Naziri | 5 |
| Rhianne Barreto | Sophie | 5 |
| Justin Salinger | Carl Meisner | 5 |
| Mark Bazeley | Robert Gelder | 3 |
| Claudia Trujillo | Teresa | 3 |
| David Avery | Stephen Mannion | 3 |
| Emma D'Arcy | Sonia Richter | 2 |
| Joanna Kulig | Johanna | 2 |
| Caitlin Innes Edwards | Grant | 2 |
| Natasha Atherton | Kim | 2 |
| Benno Fürmann | Dieter | 1 |
| Phaldut Sharma | Tom | 1 |
| Andy Nyman | Jacobs | 1 |
| Peter Ferdinando | Lukas | 1 |
| Anna Devlin | Gina | 1 |
| Paddy Rowan | Young Guard | 1 |
| Lyndsey Marshal | Rachel | 1 |
| Belén Fabra | Marta Ferrán | 1 |
| Colin Stinton | Tom Kaladski | 1 |
| Clara Segura | Alba Paredes | 1 |
| Jill Winternitz | Rachel | 1 |
| Ellie Piercy | Bethany McGovern | 1 |
| Gary Anthony Stennette | Ultrax Man | 1 |
| Faisal Mohammed | Utrax Driver | 1 |
| Georgia Goodman | Suited Woman at Trial | 1 |
| Sam C. Wilson | Costigan | 1 |
| Leander Vyvey | Male Nurse | 1 |
| Mariona Tena | Admin Woman | 1 |