The character Camilla Fritton (Rupert Everett) is a parody of Queen Camilla, the Duchess of Cornwall in both mannerisms and dress.
When Geoffrey and Camilla meet again, she says "Another time!" and he answers "Another country!", which is the title of the movie, in which Rupert Everett and Colin Firth first starred together.
There are many references to Pride and Prejudice (1995). For example: Fritton's dog is Mr D'Arcy, one of the girls mentions Colin Firth, Colin Firth dripping in water after falling into the unused fountain and Stephen Fry asking the question "Which book was originally titled "First Impressions" (A: Pride and Prejudice).
In the film, it is shown that the rival school of St Trinian's is Cheltenham Ladies' College. This is the school that Talulah Riley's character Annabelle Fritton had previously attended. This is also the school that Talulah Riley herself has previously attended.
The animated sequence during the heist plan are a stylistic nod to the original St. Trinian's cartoons drawn by Ronald Searle that inspired the movies.