The Archdiocese of Melbourne is a Latin Rite metropolitan archdiocese in Melbourne, Victoria, Australia. Erected initially in 1847 as the Diocese of Melbourne, a suffragan diocese of Archdiocese of Sydney, the diocese was elevated in 1874 as an archdiocese of the Ecclesiastical Province of Melbourne and is the metropolitan for the suffragan dioceses of Sale, Sandhurst, Ballarat, and the Ukrainian Catholic Eparchy of Ss Peter and Paul. The Archdiocese of Hobart is attached to the archdiocese for administrative purposes. St Patrick's Cathedral is the seat of the Archbishop of Melbourne, currently Peter Comensoli, who succeeded Denis Hart on 1 August 2018.

The Archdiocese of Sydney is a Latin Church ecclesiastical territory or archdiocese of the Catholic Church. Its episcopal see is Sydney, New South Wales, Australia.