Waterfall is a small suburb in southern Sydney, in the state of New South Wales, Australia. It is 38 kilometres south of the Sydney central business district in the Sutherland Shire.
Waterfall is bordered to the north by the suburb of Heathcote, with Engadine further north; by The Royal National Park to the east; and by Heathcote National Park to the west. Helensburgh is the next town, travelling south. Waterfall marks the southern border of the Sutherland Shire. It is approximately 200 metres above sea level.
Waterfall has only six streets. Its local school has only two rooms which have kindergarten to 2nd class in one room, and 3rd class to 6th class in another. The bushland gives the small suburb a natural surrounding and walking tracks lead from it into the neighbouring national parks. To the west is a dammed lake and behind it is Mount Westmacott.