Wainui River (Bay of Plenty)

The Wainui River is a river of the Bay of Plenty Region of New Zealand's North Island. It flows north from the Kaimai Range to reach Tauranga Harbour 10 km south of Katikati. The catchment has 191 km of stream margins. 41% of the catchment remains covered in native bush, but 48% is under pasture and suffers soil erosion.

The river includes 3 waterfalls of up to 10 m, which have been kayaked.

The 210 ft long former East Coast Main Trunk railway bridge is designated as the limit of the Coastal Marine Area. Downstream, a 3-span 31 m bridge takes SH2 over the river.