- Harry: "Well, it'll be hard work, pretending to Aunt Marge I got to that St Whatsits-"
- Uncle Vernon: "St Brutus's Secure Centre for Incurably Criminal Boys!"
- Harry: "Exactly. It's a lot to remember. I'll have to make it sound convincing, won't I? What if I accidentally let something slip?"
- Uncle Vernon: "You'll get the stuffing knocked out of you, won't you?"
- — Harry Potter stands his ground against Uncle Vernon's threats[src]
St Brutus's Secure Centre for Incurably Criminal Boys is apparently an institution for "mentally subnormal" and violent adolescent males. This was the centre that Vernon Dursley told his sister Marge he was sending Harry Potter to school. Saint Brutus is the patron saint for this school. Whether this school actually exists in the Muggle world, or that it was simply invented by Uncle Vernon to hide Harry's true nature and school from other Muggles and to insult him is unclear, but there is in fact no Saint Brutus, so it is most probably imaginary. He described it as a "first-rate institution for hopeless cases."
In his third year Harry was forced to pretend he was being sent to St Brutus's in exchange for Vernon's signature on his Hogsmeade permission form, because Vernon was so worried and fearful that Marge would somehow find out about Harry's true magical identity. As part of that ruse, he asserted that students there were customarily disciplined with a cane and were frequently beaten for misbehaviour. However, as Harry unintentionally inflated Marge, he did not receive Uncle Vernon's signature.
By the summer of 1995, even the neighbourhood children in Little Whinging had been told that Harry supposedly attended this institution, and a result they were somewhat fearful of him. Despite this, they were in general much more afraid of Dudley Dursley and his gang, who had a fearsome reputation for physically bullying children, whereas Harry left the neighbourhood children alone.
Brutus was the cognomen of a prominent ancient Roman family, the most famous member possibly being Marcus Junius Brutus the Younger, a politician known for his role in the assassination of Julius Caesar. A Brutus of Troy is also, according to legend, the founder of Great Britain.
- Harry Potter and the Prisoner of Azkaban (First mentioned)
- Harry Potter and the Prisoner of Azkaban (film) (Mentioned only)
- Harry Potter and the Goblet of Fire (Mentioned only)
- Harry Potter and the Order of the Phoenix (Mentioned only)