Haydon School is a mixed secondary school and sixth form in the Northwood Hills area of the London Borough of Hillingdon, Greater London, for students aged 11 to 18. On 1 April 2011, Haydon School became an Academy.
The school was formed in September 1977 from the union of St Nicholas Grammar School and St Mary's Grammar School for Girls.
It was named after the local family, as was Haydon Hall. Alice Spencer, Countess of Derby, had the hall built in 1630.
Haydon was a designated language college teaching students foreign languages.
At GCSE-Level, the school offers Latin and community languages as well as: Arabic, Bengali, Greek, Gujarati, Hebrew, Hindi, Punjabi, Persian, Polish, Portuguese, Russian, Turkish, Urdu
The Peter Woods building was opened on Thursday 9 July 2009 by former headmaster and namesake Peter Woods.
Haydon School has over 500 students in its sixth form. It offers advanced level courses on site.
For notable pupils of St Nicholas Grammar School, see that article.