The Metropolitan Cathedral of St Mary is the cathedral church of the Roman Catholic Archdiocese of Sydney and the seat of the Archbishop of Sydney, currently Cardinal George Pell. The cathedral is dedicated to "Mary, Help of Christians", Patron of Australia. St Mary’s holds the title and dignity of a minor basilica, bestowed upon it by Pope Pius XI in 1930.

St Mary's is the largest church in Australia, though not the tallest. It is located on College Street in the heart of the City of Sydney where, despite the high rise development of the Sydney central business district (CBD), its imposing structure and twin spires make it a landmark from every direction.