The school commenced in 1968 as one room at Ss Peter and Paul’s Primary School, East Doncaster.

During 1969, three portable classrooms were purchased from East Doncaster and moved to the present site on Williamsons Road. These three portables, along with other portable classrooms, were bricked together to form the main building. Children moved into this block at the commencement of term three, 1969.

St Gregory’s received formal registration from the Registered Schools Board in February, 1970, under the direction of its first Principal, Teresa Bushell. Fr John Mullally was the first Parish Priest.

The present Parish Priest, Monsignor Anthony Ireland, has been at Doncaster since September, 2009.

Michelle Verna was appointed Principal in December, 2017.