| Name | Character | Episodes |
|---|---|---|
| Siobhan Finneran | Marie-Louise O'Dell | 6 |
| Sean Bean | Mark Cobden | 3 |
| Stephen Graham | Eric McNally | 3 |
| Bella Ramsey | Kelsey Morgan | 3 |
| Jack McMullen | Daniel | 3 |
| Julie Graham | Lou Harkness | 3 |
| Jodie Whittaker | Orla O'Riordan | 3 |
| Sue Johnston | June Cobden | 3 |
| David Calder | John Cobden | 3 |
| Sophie Willan | Maeve Riley | 3 |
| Matilda Firth | Nancy O'Riordan | 3 |
| Kevin Harvey | Paul McAdams | 3 |
| Paddy Rowan | David McNally | 3 |
| Hannah Walters | Sonia McNally | 3 |
| Lisa Millett | PO Martin | 3 |
| James Nelson-Joyce | Johnno | 3 |
| Faye McKeever | Tanya | 3 |
| Tamara Lawrance | Abi Cochrane | 3 |
| Brian McCardie | Jackson Jones | 3 |
| Dean Fagan | Stevie | 3 |
| Franc Ashman | Governor Cameron | 3 |
| Terence Maynard | Kavanagh | 2 |
| Anna Madeley | Anne Warren | 2 |
| Bobby Schofield | Baz | 2 |
| Nabil Elouahabi | Patterson | 2 |
| Shahid Ahmed | Sarfraz Jawad | 2 |
| Philip Barantini | Floyd Walker | 2 |
| Jonathan Harden | Brendan Murphy | 2 |
| Natalie Gavin | Officer Jardine | 2 |
| James Corrigan | Rob Cochrane | 2 |
| Shaun Mason | Flanagan | 2 |
| Aneurin Barnard | Bernard | 1 |
| Angela Wynter | May Sinclair | 1 |
| Andrew Knott | Alexander Doyle | 1 |
| Jumayn Hunter | Stanley Timmins | 1 |
| Christopher Middleton | Celebrant | 1 |
| David Crellin | Judge | 1 |
| Philip Hill-Pearson | Orla's Bar Boss | 1 |
| Lizzie Hopley | Judge | 1 |
| Marie Critchley | Helen Wilson | 1 |
| Bridgitta Roy | Prosecution Barrister | 1 |
| Michelle Butterly | Nurse Garvey | 1 |
| Stephen Whitfield | Chairperson | 1 |