The village of Compton Bassett lies close to the western escarpment of the Marlborough Downs. The church of St Swithin is located on an Upper Greensand rise.

The earliest fabric is a recently discovered wall outside the church, possibly Anglo-Saxon. The nave has arcades of the early 13thc. The N is earlier than the S arcade. Some of the fabric of the nave walls may date from the late 11thc. or early 12thc.

In Domesday Book, there is no mention of a church, but three men hold land: 'Pain holds Compton Bassett of Humphrey de L'Isle. Leofnoth held it TRE.'; 'William d'Andrieu holds Compton Bassett of William de Eu'; 'Thorkil holds [land in] Compton Bassett he himself held it TRE.'.

After the church was built in the later 12thc, it was given to Bicester Priory.

The clerestory is Perpendicular. The chancel dates from 1865, a date commemorated on rainwater goods.