St. Mary's Diocesan School for Girls is an Anglican private boarding school for girls situated in Hillcrest, Pretoria in the Gauteng province of South Africa, St Mary's DSG was founded in 1879 by the Rt Revd Henry Bousfield, the first Bishop of Pretoria.

[1] For 75 years of its existence the school was run by the nuns of the Community of St Mary the Virgin.

The Headmistress resigned and return to England and 25 pupils remained at St Etheldreda's.

Finally the great day came when the tour Sisters arrived at the Pretoria station in September 1903.

A new era dawned during which the school developed into an efficient highly regarded and institution under the capable and loving guidance of Sisters.