The school opened in September 1971 and was originally called Unsworth Comprehensive School. Its initial enrollment was 146 pupils. In 1983, the school merged with Whitefield High School and was renamed Castlebrook High School. In 2015, Mr Settle who was a classroom assistant at Castlebrook High School was arrested for grooming a boy, aged 13. Mr Settle created fake Facebook accounts to pretend to be a 18 year old boy called James and a 13 year old boy called Matthew. Mr Settle was arrested for 18 months and has been put on the sex offenders list for 10 years.
Intake and catchment
It has a wide-ranging catchment area with some pupils travelling from central Manchester or neighbouring Bury and Salford. Some even come from as far as Bolton.
Possible closure
Throughout 2006, along with several other schools in the wider Bury borough, it had been under a sustained threat of closure. It is believed that there will be 2,000 fewer high school pupils in Bury, so Bury Council wanted to close two high schools in the area. It was possible that Castlebrook would amalgamate with nearby Philips High School, or that either Castlebrook or Philips will be closed. , 806 pupils attend the school. In 2016, the school was deemed inadequate by Ofsted, as a result, the Shaw Education Trust took Castlebrook under their wing. There is however, a new building proposed, which is due to begin in January 2018 and accept students around May 2019 if all work is completed on time. As of 2017, 903 pupils approx. attend the school.
Talent of the school
The school has been known for its great musical and theatrical ability and has staged many productions, musicals and musical, from Hobson's Choice, My Fair Lady, West Side Story and most recently in 2006 one of the first, if not the first, comprehensive school to perform the musical Thoroughly Modern Millie. The school has also been known to create its own musicals and stage them themselves, for example in the year 2001 the school staged a production called Sold Out which was written by the performing arts staff of the school. In 2017 Little Shop of Horrors was performed by the pupils of Castlebrook High School, with a sell out 2 of the 3 nights the show was performed. The school's GCSE results have been improving greatly over the last few years; with 61% of pupils achieving 5 A*-Cs in 2008, up to 76% in 2009 and to 80% in 2010, the highest the school has ever achieved. As of latest Castlebrook gets the highest GCSE results in the Construction BTEC course in England.
