St Luke's Grammar School is a dual campus independent Anglican co-educational primary and secondary day school, located on the Northern Beaches of Sydney, New South Wales, Australia. The school was founded in 1993 as the amalgamation of Roseby Preparatory School, Peninsula Grammar School and St Luke's Anglican School for Girls. Geoff Lancaster is the 3rd Principal of St Luke's Grammar School, after Jann Robinson (2005–2020) and John Scott (1993–2004).