In the 11th century Asgar, a Saxon thegn and standard bearer to Edward the Confessor owned the manor of Aynho.

After the Norman conquest of England he was forced to cede the manor to Geoffrey de Mandeville, whose family retained it for several generations.

Late in the 12th century Roger and Alice FitzRichard founded the Hospital of Saints James and John in Aynho to care for the poor, the sick and the infirm.

As part of Chiltern's Evergreen 3, the junction was relaid and upgraded for higher speeds and a new panel was fitted to Banbury South signal box.

[10] The M40 motorway now runs close to the west of the village with the nearest access at junction 10, with the A43 trunk road about 3.5 miles (5.6 km) south.

Residents have included the 17th-century politician Sir Ralph Winwood, the 19th-century Irish-based judge Charles Burton, the 19th- and 20th-century architect Philip Speakman Webb and the 20th-century mathematician Mary Cartwright.

About half a mile outside the village, there is a public house, the Great Western Arms, controlled since 2009 by the Hook Norton Brewery.