St John's Cathedral is the cathedral of the Anglican Diocese of Brisbane and the metropolitan cathedral of the ecclesiastical province of Queensland, Australia. It is dedicated to St John the Evangelist. The cathedral is situated in Ann Street in the Brisbane central business district, and is the successor to an earlier pro-cathedral, which occupied part of the contemporary Queens Gardens on William Street, from 1854 to 1904. The cathedral is the second-oldest Anglican church in Brisbane, predated only by the extant All Saints church on Wickham Terrace (1862). The cathedral is listed on the Queensland Heritage Register.

The Anglican Diocese of Brisbane, also known as Anglican Church Southern Queensland, is based in Brisbane, Queensland, Australia. The diocesan bishop's seat is at St John's Cathedral, Brisbane. The diocese stretches from the south-eastern coastline of Queensland, down to the New South Wales border and west to the Northern Territory and South Australian borders. The diocese currently markets itself as "Anglican Church Southern Queensland" (ACSQ). The "Anglicare Southern Queensland" brand is also heavily promoted by the diocese.