St John's contains two memorials for the First World War. The stained glass window features a young man with a halo around his head, dressed as a medieval knight in armour, holding aloft the Australian flag on his lance. A cherub is looking down on him. It was dedicated on 15 October 1916. The adjacent plaque is made of white marble, with veterans' names engraved and blackened. The small cross and inscription above their names are in gilt. A small relief of a poppy is positioned at the apex of the plaque.