Ashburton is on State Highway 1 86 km south of Christchurch. The Main South Line runs through the centre of town, but passenger trains ceased on 10 February 2002. The town is the centre of a rich agricultural and pastoral farming district, part of the Canterbury Plains. It has one large suburb, Tinwald, south of the town and the Ashburton River. Tinwald was the junction for the now-closed Mount Somers Branch railway line.