Joining the cast are Lena Headey, Lily Cole, Toby Jones, Celia Imrie, Anna Chancellor, and Gemma Arterton. Playing some of the modern-day students are rising talents Talulah Riley, Tamsin Egerton, Amara Karan, Paloma Faith Bloomfield and Antonia Bernath.
As previously reported, the cast is led by Rupert Everett, Colin Firth, Caterina Murino, Russell Brand, Stephen Fry and Jodie Whittaker.
The shoot started March 25 with Oliver Parker and Barnaby Thompson both co-directing and co-producing. Ealing's Fragile Films is producing and Entertainment Film Distributors has UK rights. Other backers include the UK Film Council's Premiere Fund, with bank financing from Investec.
Ealing Studios International is handling sales.
St Trinian's is produced and directed by Oliver Parker (The Importance of Being Earnest, An Ideal Husband) and Barnaby Thompson (Wayne's World 1 & 2, Spiceworld, An Ideal Husband) and is written by Piers Ashworth and Nick Moorcroft.