Knox Grammar School is an independent Uniting Church day and boarding school for boys, located in Wahroonga, New South Wales, an Upper North Shore suburb of Sydney, Australia. Founded in 1924 by the Presbyterian Church of Australia as an all-boys school named after John Knox. The school has since grown, branching out into a large Senior School and a Preparatory School, enrolling approximately 2900 students. The school also caters for approximately 160 boarding students from Years 7 to 12.