This sequel to The Belles of St Trinian’s (1954) finds headmistress, Miss Fritton (Alastair Sim) under lock and key in one of Her Majesty’s Prisons and the St Trinian’s girls under the protection of the Army.
Flash Harry (George Cole), meanwhile, is in Rome running the “St Trinian’s Marriage Bureau” and trying to set a wealthy Italian prince up with one of the sixth form girls from the school.
The Prince tells Harry to bring all the sixth formers to Rome so the girls hatch a plan to ‘win’ (through fair means or foul) a UNESCO school’s competition with a trip to Europe as its prize.
Meanwhile, diamond robber Joe Mangan (Lionel Jeffries) tries to take shelter from the police in the school and ends up “chaperoning” the girls on their trip, disguised as their new headmistress, Dame Maud Hackshaw (Judith Furse).
Let loose in Europe, it’s not long before St Trinian’s have succeeded in endangering European relations.
Undercover policewoman Ruby Gates (Joyce Grenfell) follows them and has a brief romantic encounter with Captain Romney Carlton-Ricketts (Terry-Thomas), the shady owner of the dilapidated coaches used on the school trip.
Sergeant Ruby Gates
Miss Amelia Fritton
Superintendent Sam Kemp-Bird
Dame Maud Hackshaw
Italian Police Inspector
Prince Bruno’s mother
Charles Lloyd Pack