Swyncombe lies in the Chiltern hills around 5km S of Watlington and 11km NW of Henley-on-Thames. The settlement is dispersed amongst several hamlets. The church lies in a hollow on relatively flat ground close to the manor. It dates from the 11thc. and consists of a nave with S porch, chancel and, somewhat unusually, an apse. The dedication to St Botolph (d. 680), an East Anglian abbot, is unusual in Oxfordshire, and perhaps reflects East Anglian connections via the nearby Icknield Way. The church was restored in 1831, 1845 and 1850. The surviving Romanesque features are the blocked N nave doorway, a pillar piscina, a font and part of the apse arch.

In 1066 the manor of Swyncombe may have belonged to Wigod of Wallingford, passing after the Norman Conquest to Miles Crispin.  Before 1086 Miles and his tenants (Hugh fitz Miles and Richard fitz Rainfred) granted it to the Norman abbey of Bec, which held the manor and advowson until their confiscation in 1404 during the wars with France (VCH).

Napier (1858) describes the church and its restorations by Clarke in 1831 and 1845 and then by Ferrey in 1850.

The components of the pillar piscina were found in the foundations of the first porch when it was replaced in 1850 by Ferrey. Napier shows it assembled in 1858; Pevsner and the HE listing refer to it being in fragments in the W window. By 2025 it was assembled again, and placed next to the altar.

A blocked S doorway halfway along the length of the church suggests that there may originally have been a single central doorway giving access to a longer nave with a chancel beyond, as at Coln Rogers, Gloucestershire. The existing S doorway is almost opposite the blocked Norman N doorway, which is relatively plain. These openings may have been made when the new chancel arch was built, possibly when the church came into the ownership of Bec Abbey, that is towards the end of the 11thc.

The chancel arch was widened by Clarke in 1831, so it is not possible to know whether it originally matched the apse arch. The R impost of the apse arch appears to be a modern reconstruction.

As two of the faces of the piscina show little sculpture, it may have backed on to a wall.