Duffys Forest is a suburb of northern Sydney, in the state of New South Wales, Australia. Duffys Forest is 28 kilometres north of the Sydney central business district in the local government area ofWarringah Council. Duffys Forest is considered to be part of the Northern Beaches region and the Forest District.
Waratah Park Earth Sanctuary was a popular tourist attraction in Duffys Forest, famous as the film set of the popular television series Skippy the Bush Kangaroo. Much of the set and props are still there, although since being closed in August 2009 all of the animals including descendants of the kangaroos used in the series have now been removed.
The 'Duffys Forest Ecological Community' is an endangered ecological community of the Sydney basin.