John Mason School is a state secondary school in the town of Abingdon, Oxfordshire, in the United Kingdom. Established as an old grammar school in 1960, the school has now grown considerably, with, as of 2003, approximately 1000 pupils.

The school logo is that of the Griffin, and has a motto of, "Happy school, high standards, honourable service". The school colours are orange and grey. The school has three housess, Ock, Stert, and Thames, of the colours green, red and blue respectively.

The school was named after the 16th century English diplomat, Sir John Mason.