Built in 1902 as the Technical School at Tetbury Hill but became the County Secondary School when the County Council took over responsibility for secondary education under the 1902 Education Act. From an early date this was known as the 'grammar school'. The 1918 Education Act raised the school leaving age to 14 but parents of pupils here had to promise to keep their children at school until they were 16. In 1921 an adjoining building was bought and the school expanded to 120 pupils. Until the 1944 Education Act parents had to pay for their children to attend, although there were county scholarships and also Old Corporation scholarships for Commoners' children.
The school became Malmesbury Grammar School and in 1948 had about 240 pupils. In 1964 a new school was built 750 metres to the north at Filands and when the comprehensive system was introduced in 1971 this became the Lower School of Malmesbury School. The buildings at Tetbury Hill were firstly used for a new junior school and then largely demolished.