The Augustinian church, sacristy, oratory and priory comprise one whole block (insula) of Valletta between Old Bakery, St John, Old Mint and St Mark streets.

This current church replaced an earlier one which was adjacent to it and facing in the opposite direction. The remains of the earlier church are still visible in the underground spaces beneath the current Augustinian convent. St Augustine is one of the churches built during the early years of Valletta. The foundation stone was laid in 1571.

A life-size statue of St Augustine of Hippo dressed as a bishop is located on Old Bakery Street corner with St John Street. An earlier statue was destroyed in April 1943.

The plan of this church differs from most other parish churches as it is centrally planned in a cruciform layout with a dome over the crossing.

The sacristy consists of a rectangular space with a second attic and vaulted roof. The priory building is mostly on three floors at Old Bakery Street with another two floors of rented housing and shops beneath the convent onto Old Mint Street. The oratory occupies part of the ground floor beneath the Augustinian convent. Structural changes were made in 1845, converting part of it into a sacristy.

The Malta Environment and Planning Authority scheduled the parish church as a Grade 1 monument on March 28, 2008 as per Government Notice 276.