Canberra Girls Grammar School (CGGS) is an independent, Anglican, day and boarding school predominantly for girls, located in Deakin, a suburb of Canberra, the capital of Australia.

Established in 1926 as St Gabriel's School, by the Church of England religious order, the Community of the Sisters of the Church, Canberra Girls Grammar is the oldest private day and boarding school in Canberra. It has a non-selective enrolment policy and caters for approximately 1,300 students, with co-education from Early Learning (preschool) to Year 3, and girls only from Years 4 to Year 12. Boarding facilities are available on the Senior Campus for up to 80 students in Years 7 to 12. CGGS is also licensed to offer the International Baccalaureate Primary Years Programme and Diploma Programme (for Years 11 and 12). It is a candidate school for the MYP from Yrs 6 to 9.

Canberra Girls Grammar School is affiliated with the Alliance of Girls Schools Australasia (AGSA), the Associated Southern Colleges (ASC), the Association of Heads of Independent Schools of Australia (AHISA), the Australian Boarding Schools' Association (ABSA), and is a member of the Association of Heads of Independent Girls' Schools (AHIGS).