Clewer House School was a 19th-century grammar school in Clewer, Windsor, Berkshire for boys.
The course of study includes instruction in Classics, Mathematics, French, German, English, Singing, Gymnastics, etc. to about 130 boarders. Pupils are prepared for the Oxford and Cambridge Local Examinations, at which 248 certificates, 92 in honours, had been gained by pupils up to 1873.
Clewer House was a manor house built c. 1795. In the early 1800s the house was occupied by John Ramsbottom (1778–1845), who served as MP for Windsor from 1810 to 1845 and moved to Old Windsor c. 1835.
The school was founded in 1839 by Rev. William Redford Harris, a magistrate in Windsor who became the town's mayor in 1864. The school had an excellent academic reputation for a number of decades but was closed down around the turn of the 19th century.