The school was proposed in May 1955 in a public notice issued by Somerset County CouncilEducation Committee, to eventually comply with the 1944 Education Act which had required secondary education for all, which had previously been provided by "all age primaries" in the area. The new school, which was originally called Chew Magna Secondary School, opened on 13 January 1958, although the official opening by Sir James Turner then president of the National Farmers Union was on 23 May. In 2008, the school celebrated its 50th anniversary. In the same year a wind turbine was installed at the school, and unveiled by the local MPDan Norris. The turbine was supported by the Go Zero campaign based in Chew Magna who have also supported a similar initiative in Tamil Nadu, India., In April 2009, ex Head Teacher, Mark Mallet, did a parachute jump from 10,000 feet above ground level in aid of a new Art and Sixth Form block which was completed in August that year. On 1 August 2010, Chew Valley School became a foundation school. A letter to parents described the aims as "to use Foundation Status to help to raise standards and make a direct contribution to raising achievement and improve the well being and aspirations of students." As part of the status change there was a legal transfer of land from the Local Authority to the School. The school's letterhead now reads "A Foundation School serving the whole community" In November 2015, ex Head Teacher Mark Mallet asked parents for monthly standing orders to overcome a budget deficit.
Academic achievement
In the most recent Ofsted report, in 2011, the school received was rated 'Outstanding', higher than previous ratings in 2004 and 2008. In 2010 68% of students achieved five or more A*-C including English and Mathematics GCSEs. In March 2011 three students from the school's Sixth Form won the English Speaking Union's Great Shakespeare Debate, beating eleven other schools including Eton, Wellingborough, and Magdalen College School, Oxford.
Performing arts
The school became a Specialist school in the Performing Arts in 2003. Productions are put on each term, there is an annual dance festival, concerts, and cabarets. Then in year of 2017 it stopped being a Specialist School and became an Academy.
Sport
After numerous years of poor sports facilities a lottery grant enabled the school to build a new gymnasium and an all-weather pitch for both school and community use. This grant followed a similar grant for Chew Valley Rugby Club.