Gregory Hills is built on land which was formerly St Gregory's College farm. This land was given to the Marist Brothers by Thomas Donovan in the 1920's for the development of a boys school to teach young men the skills to have careers on
the land.

Thomas Donovan was born in Sydney in 1843. As a barrister he was keenly interested in public affairs and a noted philanthropist. As well as the donation of the land where Gregory Hills now sits, he gave funds for the foundation of Newman College at the University of Melbourne and the establishment of the Donovan Astronomical Trust which continues today to promote the education of Astronomical Science in Australia.

Mr Donovan gave the Campbelltown property to the Brothers as well as the name 'St Gregory's'. Much of the early school infrastructure including the Chapel, classrooms and the first dormitory were also donated by Mr Donovan.

St Gregory's College opened in 1926 to an unassuming start. From just two students St Gregory's College has today grown to 1100 students and remains true to the Marist Brothers education commitment.

Along with his philanthropic ventures, Thomas Donovan also commenced the study of Elizabethan drama which led him to edit texts on William Shakespeare.