St Hearts, formerly Bleakwood Academy, is the main setting for the show. The MI High spies go to the school and their spy handler, Frank, works as the caretaker there. We also have subplots surrounding two of the teachers (Mr Flatley and Mr McNab/Mrs King) and a few of the students in every episode.
Because of the top secret MI9 base under the school, it is often used for high profile occasions and visits from VIPs. MI9 missions regularly use the staff and students for cover stories. Frank's caretaker job is just a cover and the MI High team are students at the school.
- Kenneth Flatley: Headmaster
- Mr McNab: Deputy Headmaster
- Mrs King: Deputy Headmistress
- Frank London: Caretaker
- Stella Knight (Miss Freeman): Supply teacher
- Walter M Dainbridge: Headmaster until 1941
- Dan Morgan (MI High)
- Aneisha Jones (MI High)
- Tom Tupper (MI High)
- Zoe (MI High)
- Keri Summers (MI High)
- Roly Donaldson
- Byron Ditchwater
- Melissa Allbright
- Lady J
- Billy Bagshaw (1941)
- Emily Cartwright (1941)
- Jack Watkins (1941)
- In Frankenstein, St Hearts celebrated it's 100th birthday. It was also discovered that KORPS had a secret base under the school.
- Goof: In Grosse Encounters, the Area 5.1 map read St Hearts, although it is unlikely the map had been made after the recent name change.
- Goof: In The Beginning the school sign from 1941 read Saint Hearts, when it should have read Bleakwood Academy due to the school name not changing for another 70 years.