Canberra Grammar School is a co-educational, independent, day and boarding school located in Red Hill, a suburb of Canberra, the capital of Australia.

The school is affiliated with the Anglican Church of Australia and provides an education from preschool to Year 12 for boys and girls. In October 2015, the school announced that it would extend co-education to all years, commencing in 2016 with an intake of girls in Years 3 and 4. By 2018, the school became fully co-educational.

The school was founded in 1929 when the existing Monaro Grammar School was relocated to Canberra from Cooma. The foundation stone was laid on 4 December 1928 by Prime Minister Stanley Bruce. Initially, it was attended by only 63 students, but the school has grown considerably since the early 1950s to a total attendance of 1,749 students as of June 2015.

The school has educated one Australian prime minister, Gough Whitlam, and has a long list of notable alumni.

The school consists of 5 main campuses: Red Hill Southside, Red Hill Primary, Red Hill Senior, the Early Learning Center (ELC) and Northside Campbell.