Watchfield is a village and civil parish in the Vale of White Horse in on the edge of southwest Oxfordshire, southern England, about 3 miles (4.8 km) southeast of Highworth in neighbouring Wiltshire. Watchfield is about 1 mile (1.6 km) north of the village of Shrivenham. Both villages used to be on the main road between Oxford and Swindon, which is now the A420 road.