Kingston Grammar School is an independent co-educational day school in Kingston upon Thames, south-west London. The school was founded by Royal Charter in 1561 but can trace its roots back to at least the 13th century. It is a registered charity under English law. In 2015 the GCSE results recorded 81.2% of all grades as A or A*, and at A-level 62.7% of all grades were A or A*. The Good Schools Guide described the school as "An academic school with a modern edge".