St Mary's School is an independent day and boarding school in Calne, Wiltshire, for girls aged 11 to 18. The school is a registered charity. St Mary's Calne is the top performing independent school in the South West, ranked by 2017 examination results published in The Sunday Times Schools Guide 2018, 'Parent Power' and ranks in the top 3 best girls' boarding schools (based on A*-A grades in A Levels, 2018) in the Education Advisers' Best UK Schools list.