Only a few prehistoric and Roman finds have been made in the parish. The prehistoric finds are all Neolithic and are all flint blades that were found near Swanbourne School and in excavations for the main water pipeline. The Roman pottery was found near the school and also in a ballast hole at Swanbourne Station. A few remnants of Saxon times have also been recorded, such as the fragment of quern in St Swithun’s churchyard and the records of the tenth century boundary with Winslow, which can be traced in the form of a linear bank. Place-name evidence of Buxlow Farm suggests that this was the site of a Saxon mound and possible meeting place.
There are several mounds around the parish that were probably medieval windmill mounds, such as the one on Church Hill, and the Swanbourne Tumps on the parish boundary with Hoggeston. Other earthworks are remains of medieval houses and fields, such as the house platforms at Duck End and the house platforms, ridge-and-furrow and fishpond east of Swanbourne village and the house platforms on the Weedon-Mursley water pipeline. A medieval horn comb was found at this latter site and medieval pottery was found in a watching brief in the churchyard. St Swithun's church is the oldest standing building in Swanbourne, with the nave, chancel and tower dating to 1230, though the latter was rebuilt in the fifteenth or sixteenth century. It was restored in the nineteenth century.
Some of the secular buildings in the parish date to the end of the medieval period, being fifteenth century cruck-built houses such as Barracks Row and 21 Nearton End. Other listed buildings are sixteenth and seventeenth century timber-framed buildings, and many of these have later eighteenth or nineteenth century alterations. The Salden estate map of 1599 marks the position of two windmills, at Oakham Hill and Millpossets Field. It also records ‘Standing Walls’, though what and where this was is now not known.
There was a great deal of activity in the eighteenth and nineteenth centuries in the form of altering earlier buildings and building new ones, such as Swanbourne House, which is now Swanbourne House School. A garden house, built in 1865, is now the school chapel. The first edition nineteenth century OS maps mark the site of many gravel and sand-pits, track-ways and field barns. The latter were lost as fields grew larger with greater mechanisation of agriculture. A Volunteer Rifle Range was also recorded on these maps, west of the school.