Mount Grenfell Historic Site is an Aboriginal rock art site, about 50 kilometres west of Cobar, in the arid lands in central west New South Wales, Australia. It is a spiritually important place for its Aboriginal owners, the Ngiyampaa Wangaaypuwan people. Hundreds of ancient rock drawings of humans, animals and the natural environment can be found at this historically invaluable site.
On 17 July 2004, the site was handed back by the Australian government to the Ngiyampaa Wangaaypuwan people, but is leased back to the NSW government.