Berkhamsted School is a public school, in the market town of Berkhamsted, in Hertfordshire, England. The present school was formed in 1997 by the amalgamation of the original Berkhamsted School, founded in 1541 by John Incent, Dean of St Paul's Cathedral under charter from King Henry VIII Berkhamsted School for Girls, established in 1888, and Berkhamsted Preparatory School. The merged school was initially called Berkhamsted Collegiate School, but reverted to Berkhamsted School in 2008. In 2011 Berkhamsted School merged with Heatherton House School, a girls' preparatory school in Amersham, to form the Berkhamsted Schools Group. The Group acquired Haresfoot School in Berkhamsted and its on-site day nursery in 2012, which became Berkhamsted Pre-Preparatory School for children aged three to seven, and Berkhamsted Day Nursery.

Berkhamsted School is a "diamond school" in which pupils are taught coeducationally in the Pre-Prep School, Prep School and Sixth Form, but separately in the traditional Senior years, between the ages of 11 and 16. The school has four main sites: the Pre-Prep School, the Prep School, the Castle Street Campus, and Kings Road Campus (the latter two being the original boys' and girls' schools respectively).

The school has a collegiate and pastoral structure. Students receive sporting, outdoor education and cultural co-curricular programmes along with activities in the local community. Richard Backhouse, previously principal of Monkton Combe School, became principal of the school in January 2016.

Notable alumni, Known as 'Old Berkhamstedians', include Graham Greene, KSI, Roman Kemp, Clementine Churchill, Sir Robin knox-Johnston and Zaha Hadid.

All Berkhamsted pupils belong to a house throughout their time at the School. Each house is run by a house-master supported by several house tutors. Together they are responsible for providing pastoral support for their pupils and serve as the primary link between parents and the school. Houses are administrative and residential units within the school. Pupils attend their house for morning and afternoon registration, to play games throughout the day, and for the majority of the administration which governs their time at the school. They also participate in school events on behalf of their house.

That at least three of the eight Senior Boys' Houses appear to be named after various fauna was not always intentional. When Swifts and Bees were formed in 1897, they were to be called 'A' and 'B' respectively, but the former's first house master considered this dull, naming his House 'Swifts'. 'Bees' is thus phonetic. 'Adders' may be wholly fortuitous; 'Reeves' and 'Hawks', now sixth form houses, add to the confusion. Richard Reeve was the school's first headmaster; Hawks was named by the apparent "fauna tradition" in 1933.

Berkhamsted School Was granted a coat of arms in 1889, adopting the arms of its founder Dean John Incent.

The school has a Latin motto "Virtus Laudata Crescit" (Virtue, when praised, grows)