Mount Saint Joseph, Milperra (commonly known as MSJ) is a Systemic Roman Catholic comprehensive single-sex secondary day school for girls, located in Milperra, a south-western suburb of Sydney, New South Wales, Australia.

Mount Saint Joseph's brother school is De La Salle Revesby Heights.

At this time the population of the area was increasing rapidly and the parishes were unable to meet the costs of building such a school.

The land was classified as Green Belt, so permission had to be sought and duly granted from the councils concerned.

[3] Mount St Joseph retains its links to the Josephite community through annual feast days and celebrations, connections to other Josephite schools in Warmun (Western Australia) and Tarma (Peru), and participation in social justice and leadership initiatives alongside the Sisters of St Joseph.