Nowendoc River, a perennial river of the Manning River catchment, is located in the Northern Tablelands and Mid North Coast districts of New South Wales, Australia.

Nowendoc River rises on the eastern slopes of the Great Dividing Range, north of the Black Sugarloaf, south of Walcha and flows generally southeast, joined by two tributaries including Cooplacurripa River and Rowleys River, before reaching its confluence with the Manning River, west of Wingham. The river descends 1,100 metres (3,600 ft) over its 115 kilometres (71 mi) course.

• Rivers of New South Wales
• List of rivers of New South Wales (L–Z)
• List of rivers of Australia

• "Manning River catchments" (map). Office of Environment and Heritage. Government of New South Wales.

31°45′S 152°04′E / 31.750°S 152.067°E / -31.750; 152.067