St Antony's school was founded in Sherborne in 1891 by the Sisters of Christian Instruction. The first sisters travelled from their mother house in Belgium to promote the education of academic and spiritual education of girls and St Antony's was the order's first establishment in the UK. The sisters established two schools on the site: St Antony's, a girls boarding school and St Joseph's which offered free education to the local community until government legislation forced it to close in the 1950s. In 1948 the demands of the Education Act led to the sisters moving the senior pupils to Leweston Manor an extensive estate which dates back to the Middle Ages when it was the property of the now defunct Leweston family. The range of buildings on the site spans several architectural epochs. The historically important Trinity Chapel is one of the first post-Reformation churches in the country whereas the core of the present school, a fine Palladian manor house was built in the late 18th century with Art Deco interior refurbishments and later additions including dining, boarding and teaching wings.
The preparatory school continued in Sherborne until 1993 when the whole school was reunited once again on the Leweston campus and the younger pupils took up residence in the redesigned Coach House.
The school amended its name in 2007 to Leweston School and Leweston Prep. The school crest remains the same, which includes the reference to St Antony's.
The carefully maintained School grounds and gardens are home to a wealth of local fauna and flora as well as a wide collection of trees some extremely rare.