| Fortitude is a place like nowhere else. Although surrounded by the savage beauty of the Arctic landscape, Fortitude is one of the safest towns on earth. There has never been a violent crime here. Until now. In such a close-knit community a murder touches everyone and the unsettling, mysterious horror of this crime threatens the future of the town itself. |
| Name | Character | Episodes |
|---|---|---|
| Sienna Guillory | Natalie Yelburton | 25 |
| Richard Dormer | Dan Anderssen | 25 |
| Darren Boyd | Markus Huseklepp | 25 |
| Sofie Gråbøl | Governor Odegard | 25 |
| Luke Treadaway | Vincent Rattrey | 25 |
| Björn Hlynur Haraldsson | Officer Eric Odegard | 25 |
| Alexandra Moen | Officer Petra Bergen | 25 |
| Mia Jexen | Officer Ingrid Witry | 25 |
| Verónica Echegui | Elena Ledesma | 21 |
| Dennis Quaid | Michael Lennox | 14 |
| Stanley Tucci | DCI Morton | 11 |
| Christopher Eccleston | Professor Charlie Stoddart | 11 |
| Michael Gambon | Henry Tyson | 11 |
| Ramon Tikaram | Tavrani | 11 |
| Jessica Raine | Jules Sutter | 11 |
| Leanne Best | Celia Donnelly | 11 |
| Jonjo O'Neill | Ciaran Donnelly | 11 |
| Phoebe Nicholls | Doctor Allerdyce | 11 |
| Aaron McCusker | Jason Donnelly | 11 |
| Lorcan Cranitch | DI Littlejohn | 11 |
| Michael Obiora | Max Cordero | 11 |
| Emil Hostina | Yuri Lubimov | 11 |
| Johnny Harris | Ronnie Morgan | 11 |
| Chipo Chung | Trish Stoddart | 11 |
| Nicholas Pinnock | Frank Sutter | 11 |
| Jessica Gunning | Shirley Allerdyce | 11 |
| Robert Sheehan | Vladek Klimov | 10 |
| Michelle Fairley | Freya Lennox | 10 |
| Parminder Nagra | Dr. Sarinda Khatri | 10 |
| Ken Stott | Erling Munk | 10 |
| Eloise Smyth | Yeva Podnikov | 10 |
| Rune Temte | Lars Ulvinaune | 9 |
| Abubakar Salim | Boyd Mulvihill | 3 |
| Lewin Lloyd | Petter Hansen | 1 |