John Hampden Grammar School is a school in High Wycombe, Buckinghamshire in the United Kingdom. It is named after John Hampden.

The school was originally the Wycombe Technical High School founded in the building to the east of the town centre vacated by the Royal Grammar School, High Wycombe, when the latter moved to its present site to the north of the town. When the WTHS itself moved to a new site to the south of the town, it was renamed The John Hampden School, and later took on the Grammar school name.

As the original name suggested, the school was more practically orientated than the Royal Grammar, and the new building included woodwork and metalwork classrooms.

Amusingly, when in 2003, the Royal Grammar school was used as the location for two seasons of the television series That'll Teach 'em for Channel 4, the head teacher was the retired head of the John Hampden Grammar School, Andrew MacTavish.