The Funeral of Miss Fritten's dog is reminiscent of The Italian Job (1969), where the Mafia line the hill side in dark glasses to 'warn off' the gang. And in another reference to that film, when the girls blow up the shed, Tania says "you were only supposed to blow the bloody doors off".
When Colin Firth first makes his inspection of St Trinian's, and is tossed out of the Posh Totty's window, he walks to the hockey field wet, in a white shirt with his jacket over his arm. This is reminiscent of the part he played in the 1990's mini series Pride and Prejudice (1995), where he does a scene in the exact same way as depicted here.
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.
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).
The picture in Miss Fritton's study is a painting of Alastair Sim, as he played the original role in the original films. The bust that is destroyed by Annabelle's hockey blow also has the features of Sim.
When Kelly suggests they steal the 'Girl With a Pearl Earring' portrait, the Posh Totty group reply "Oh my god, you want us to steal Scarlett Johansson?", referring to the film Girl with a Pearl Earring (2003). Colin Firth, who plays Geoffrey Thwaites in this movie, played the painter in the film with Johansson.
The concept and name for St Trinian's was originally taken by Ronald Searle from St Trinnean's school in Edinburgh, which was established by Miss C. Fraser Lee and opened on 4 October 1922 with sixty girls, at 10 Palmerston Road. The school has since closed down, and is now Edinburgh University's Pollock Halls (of Residence). The school's existence became widely known when it advertised a reunion coffee party for old girls in The Scotsman in September 1955. By this time the fictional school was very well-known; the typesetter incorrectly used Searle's spelling in the advertisement. In an interview with the "Sunday Express" the headmistress firmly denied that her girls were anything like their fictional counterparts.
During a deleted scene, Thwaite is talking to his colleagues about trying to reform St Trinian's. One of his colleague's announces "Let those wildcats beware." As a heading for a newspaper article. This line is paying homage to the movie The Wildcats of St. Trinian's (1980).
It seems that the names of the St Trinian's opponents are chosen from the real names of the film's actors and actresses. For example: the Ampleforth college female contestant is named Tamsin (there's a label with her name underneath); a guy from Bedales is named Rupert; a girl from Chelterton is named Antonia. These are related to Tamsin Egerton, Rupert Everett and Antonia Bernath.
The plaster bust in the hallway is that of Alastair Sim in character as the original Miss Fritton in the original movie The Belles of St Trinian's. It can be seen twice in the early scenes of the new movie.