Trinity Grammar School is an independent, Anglican, day and boarding school for boys, located over three campuses in Summer Hill, Strathfield and Lewisham, all inner western suburbs of Sydney, New South Wales, Australia.
Founded in 1913 by The Right Reverend G.A Chambers at Dulwich Hill, the school has a non-selective enrolment policy and currently caters for approximately 2,000 students from Pre-Kindergarten to Year 12, including 30 boarders from Years 7 to 12.
Trinity is affiliated with the International Coalition of Boys' Schools, the Association of Heads of Independent Schools of Australia (AHISA), the Junior School Heads Association of Australia (JSHAA), the Australian Boarding Schools' Association (ABSA), and is a founding member of the Combined Associated Schools (CAS). The Head Master is a member of the Headmasters' and Headmistresses' Conference (UK).
The School is governed by a Council (appointed by ordinance of the Diocese of Sydney), with the Archbishop of Sydney as President.