The River Dorn is a river in Oxfordshire, England, that is a tributary of the River Glyme. The river rises from the limestone uplands of north Oxfordshire, about 1.5 miles (2.4 km) east of Chipping Norton (), and flows southeast past Little Tew; through Sandford St. Martin, where it forms part of Sandford Park's gardens; and through the Bartons: Westcott Barton, Middle Barton, where Cockley Brook joins it, and Steeple Barton — before it joins the River Glyme just east of Wootton ().