The River Wensum is a river in Norfolk, England and a tributary of the River Yare. The source of the Wensum between the villages of Colkirk and Whissonsett in Breckland, Norfolk. The river flows westward initially through the village of Raynham passing close to Raynham hall, home of the Marquis Townshend. The river then turns and follows a path to the north flowing through a number of small villages. An c18 water mill (now a hotel and restaurant) bridges the river at Sculthorpe. The river then turns and flows to the east through the market town of Fakenham where it is bridged by another c18 water mill that was in use until 1979. The river then flows in a south easterly direction passing theough the Pensthorpe Nature reserve and the village of Great Ryburgh.

The river then flows onwards through the villages Great Witchingham, Lenwade and Taverham before entering the City of Norwich. The river then merges with the river Yare to the south of the city before flowing eastward through Breydon Water to the Sea at Great Yarmouth.