Primary contact119 Prospect Road, Summer Hill
Sydney, New South Wales 2130
The School was founded in 1913 by Rev G A Chambers, Rector of Holy Trinity, Dulwich Hill, and his parishioners, as an independent Anglican Day and Boarding School for boys. In 1926 it moved from Dulwich Hill to the Summer Hill site it now occupies.
Strathfield Grammar School was purchased by Trinity in 1926 and was later incorporated into Trinity Grammar. In 1928, the School was reorganised to have a School Council appointed by ordinance of the Anglican Church, Diocese of Sydney.
In 1938 Trinity Grammar Preparatory School was formed at the Strathfield Campus, and the secondary students relocated to Summer Hill. In 2000, Trinity Grammar Junior School was established at the Summer Hill campus. The School operates as a single entity with multiple campuses.
The School Archives was established in 1975.