Banneville-sur-Ajon is a French commune in the Calvados department in the Basse-Normandie region of north-western France.
The inhabitants of the commune are known as Bannevillais or Bannevillaises.
Banneville-sur-Ajon is located some 20 km south-west of Caen and 7 km south-east of Villers-Bocage. Access to the commune is by the D121A from Saint-Agnan-le-Malherbe in the south which passes through the centre of the commune and the village and continues north to join the D8. The D171 from Landes-sur-Ajon to Préaux-Bocage passes through the north-east of the commune. Apart from the village there are the hamlets of La Fêterie in the south and Gournay in the north. The commune is almost all farmland.
The Ajon river flows through the commune from south-east to north-west continuing to join the Odon south-west of Le Locheur. The Orgeuil river rises in the south of the commune and flows north-east through the length of the commune to join the Ajon. The Ruisseau de la Rette flows from the south to join the Orgeuil.