The Woronora River is a perennial river of the Sydney Basin, located in the Sutherland Shire local government area of Greater Metropolitan Sydney, approximately 22 kilometres (14 mi) south of the Sydney central business district, in New South Wales, Australia. The Woronora River rises on the northwestern slopes of the Illawarra escarpment and has its origin from Waratah Rivulet, near Darkes Forest, and flows generally north for approximately 36 kilometres (22 mi), joined by three minor tributaries, before reaching its confluence with the Georges River, between Como and Illawong.