St Augustine's Grammar School was a Catholic grammar school on Stancliffe Road, Sharston Mount in the north of Wythenshawe off the A560, which opened in 1966. It became the upper school of St John Plessington High School (comprehensive) in 1977. This became part of St Paul's RC High School in 1984, and the Sharston site became derelict in 1987, and demolished in 1988. Another Catholic grammar school in south Manchester is St Bede's College. St Columbia's and All Hallows secondary modern catholic schools in south Manchester closed in 1975 and 1994 with staff and pupils from All Hallows transferring to St John Plessington and ultimately St Paul's.
The school was graded as 'inadequate' by Ofsted in 2015, highlighting 'serious weaknesses'.[2] In 2022 the school was graded 'good' by Ofsted.
The school is situated west of the M56 (North Cheshire Motorway). To the west nearby is Newall Green High School which closed in 2021. The present site of St Paul's on Firbank Road incorporates the original premises of St Peter's RC Primary School, which swapped property with the original St Paul's next door. St Peter's Church adjacent to the site was demolished in 1990.