The Wouri estuary, or Cameroon estuary is a large tidal estuary in Cameroon where several rivers come together, emptying into the Bight of Biafra. Douala, the largest city in Cameroon, is at the mouth of the Wouri River where it enters the estuary. The estuary contains extensive mangrove forests, which are being damaged by pollution and population pressures.

The Wouri is a river in Cameroon. Cameroon has many water bodies and amongst these are two major rivers, the Sanaga, the longest at about 525 km long and the Wouri, the largest. The Wouri forms at the confluence of the rivers Nkam and Makombé, 32 km (20 mi) northeast of the city of Yabassi. It then flows about 160 km (99 mi) southeast to the Wouri estuary at Douala, the chief port and industrial city in the southwestern part of Cameroon on the Gulf of Guinea. The river is navigable about 64 km (40 mi) upriver from Douala.