Holy Trinity Church was Sydney's first Garrison Church. The foundation stone for the Holy Trinity Church was laid in June 1840 with the first recorded service being held in May 1844.

Two major oversights are associated with this Church; the first relates to its construction - the foundation should have been laid facing North / South but was in fact laid East / West. This is considered a fortuitous oversight, however, as the renowned East Window catches the morning sun. The second is that the church was consecrated in 2000, 160 years after its founding.

Funds were raised in the late 1800's to build the church tower. The tower never eventuated so the funds were applied to roof repairs in 1938.

The Church is located in the corner of Argyle & Lower Fort Street, Millers Point. It is very close to the Sydney Observatory and approxmately five minutes walk West from The Rocks and approximately 15 minutes walk North West from Wynyard Station.