On 28 March 1840 the trustees of Holy Trinity – Osmond Gilles, Charles Mann and James Hurtle Fisher – were given approximately 40 acres (160,000 m2) of land in the area, as Glebe lands, by Pascoe St Leger Grenfell.

However, the terms of the trust deed forbade it and required an act of Parliament to alter.

The land was then immediately subdivided, named 'Trinity Gardens', and sold for housing by Wilkinson, Sando & Wyles Ltd,[3] who promised to make "liberal provision in the way of space for tennis, bowls and croquet.

"[4] North Norwood Post Office opened around 1886, was renamed Trinity Gardens in 1950 and St Morris in 1963, when the second Trinity Gardens office opened in the present area of the suburb.

[5] Trinity Gardens is in the City of Norwood Payneham St Peters local government area, the South Australian House of Assembly Electoral district of Dunstan and the Australian House of Representatives Division of Sturt.