The Royal Grammar School, High Wycombe, is a selective boys' grammar school situated in High Wycombe, Buckinghamshire, England. As a state school, it does not charge fees for pupils to attend, but they must pass the 11 plus, an exam that some primary schools administer. In February 2011, the school became an Academy.

Established by Royal Charter in 1562 (originally established as a school in 1551), it is situated on Amersham Hill to the north of the town and has a capacity of about 1,370 boys aged between 11 and 19, open Monday to Friday from 8:00am to 3:30pm and later for co-curricular activities. The school has boarding facilities and was a DfES-designated Language College until 2010. From 2007-2010, it was also a Mathematics and ICT College. OFSTED gave it a Good ranking in its 2019 inspection.