Sherborne International was formed in 1977 when it was known as Greenhill House, named after the building the students occupied both to live and to learn. For many years the School only accepted boys and remained on the Greenhill House campus until 1991 when it moved to its present location of Newell Grange.
The 1990s was an important decade as not only did the School move to a bigger site but also in September 1996 became co-educational (accepted girls). At first the girls were housed at Sherborne Girls School before moving to Westcott House, where most of the girls still reside. In January 2011, a second girls' boarding house was built which completes the present complement of five boarding houses.
Academically the School still holds true to its original ideas of providing quality teaching through small classes (usually a maximum of 8 students per class), expert tuition and careful monitoring of progress. Many members of the English department are DELTA qualified; teachers of all subjects are EFL experienced or hold the CELTA EFL qualification, even if they are not a member of the English department! New staff of all subjects are given EFL support and are observed by a member of the English department as part of their Newly Appointed Teacher programme.