The Avon River, a perennial river of the Hawkesbury-Nepean catchment, is located in the Southern Highlands and Macarthur districts of New South Wales, Australia.

Course

The Avon River rises on the western slopes of the Illawarra escarpment, near Calderwood within the Wollongong local government area and flows generally north, reaching its confluence with the Cordeaux River, south of Wilton. The river descends 155 m over its 32 km course. The river is impounded by Lake Avon, the largest of the four reservoirs within the Upper Nepean Scheme that supplies potable water for greater metropolitan Sydney. Located near Bargo, approximately 100 km south-west of Sydney, construction of Avon Dam commenced in 1921 and was completed in 1927. In 1963, the water supply was diverted to meet the increasing needs of the Illawarra region and now supplies all the Wollongong area.