St Mary's Cathedral College, Sydney

St Mary's Cathedral College (SMCC) is a systemic coeducational Catholic day school for students, located in the central business district of Sydney, New South Wales, Australia. Founded in 1824, it is among the oldest schools in the country, currently catering for approximately 830 students from Kindergarten to Year 12. The college is administered by Sydney Catholic Schools of the Archdiocese of Sydney and operates as a systemic school; it is attached to St Mary's Cathedral. It serves as the choir school for the cathedral, and the choristers of St Mary's Cathedral Choir are drawn from the college. From 1910 until 2016 the college was the responsibility of the Congregation of Christian Brothers and was latterly administered via Edmund Rice Education Australia. It was the last school in Sydney to be served by Christian Brothers as both principal and deputy principal.

In 2022, St Mary's Cathedral College announced plans to transition from a single-sex boys school to a co-educational model.