Kalu Ganga (Sinhala: කළු ගඟ; literally: Black River) is a river in Sri Lanka.

The river originates from Sri Pada Peak Wilderness Sanctuary, reaching the sea at Kalutara after a 129 km (80 mi) journey.

The mountainous forests in the Central Province and the Sinharaja Forest Reserve are the main sources of water for the river.

[1] The Edwardian manor, Richmond Castle is on the banks of the river near Kalutara.

[2][3][4] This article related to a river in Sri Lanka is a stub.