As the name Old Priory suggests, the school has historical links with a religious building. The first mention of the site is in a Saxon Deed of AD 904, now in the British Museum. This indicates that there was a building here prior to that date. The building was situated at the head of the tidal water and was a college of ordinary clergy and a free chapel.

In 1121, the Saxon College came to an end and gave place to an Augustinian Priory, which existed until its suppression in 1539. Within a short time, the buildings were ransacked and the stone removed for building all over Plympton. The extensive lands were occupied by several different families over the years. The land was known for years as Old Priory.

The school itself, built in 1968, is on the site of the ancient Priory orchard. All that is left of the former monastic buildings is the Tower House in Market Road.