| Rupert Everett |
Camilla Fritton |
| Rupert Everett |
Captain Archibald Fritton |
| Rupert Everett |
Fortnum Fritton |
| Colin Firth |
Geoffrey Thwaites |
| David Tennant |
Pomfrey |
| Talulah Riley |
Annabelle Fritton |
| Jodie Whittaker |
Beverley |
| Juno Temple |
Celia |
| Tamsin Egerton |
Chelsea |
| Toby Jones |
Bursar |
| Sarah Harding |
Roxy |
| Zawe Ashton |
Bianca |
| Montserrat Lombard |
Zoe |
| Ella Smith |
Lucy |
| Celia Imrie |
Matron |
| Clara Paget |
Bella |
| Gabriella Wilde |
Saffy |
| Cloe Mackie |
Tania |
| Holly Mackie |
Tara |
| Christian Brassington |
Peters |
| Gemma Arterton |
Kelly Jones |
| Tom Riley |
Romeo |
| Georgia King |
Juliet |
| Katherine Parkinson |
Physics Teacher |
| Pip Torrens |
Heathcote Parker |
| Steve Furst |
Arbuthnott |
| Humphrey Ker |
AD1 Member |
| Ricky Wilson |
Rockstar |
| Denise Stephenson |
Reporter |
| Zara Treherne |
Georgiana |
| Tallulah Evans |
Jemima |
| Lola Mae Loughran |
Patience |
| Paul Putner |
Steve the Barman |
| Aran Bell |
Headmaster |
| Freddie Fox |
Head Boy |
| Angus Barnett |
Drunken Sailor |
| Giles New |
Drunken Sailor |
| David Armand |
Police Officer |
| Colin Michael Carmichael |
Police Officer |
| Edith Thompson |
Tabitha |
| Bonnie Mallet |
Globe Look Out Girl |
| Paris Husty |
Globe Whispering Girl |
| Florence Grounds |
Witch Doctor Julie |
| Salaheddin Essayah |
Pomfrey's Henchman |
| Jessica Agombar |
The Banned of St Trinian's - Jess |
| Harriet Bamford |
The Banned of St Trinian's - Harriet |
| Jessica Bell |
The Banned of St Trinian's - Beth |
| Daisy Tonge |
The Banned of St Trinian's - Daisy |