Protected areas of South Australia, consisting of protected areas located within South Australia and its immediate onshore waters and which are managed by South Australian Government agencies. As of 2018, South Australia contained 359 separate protected areas declared under the National Parks and Wildlife Act 1972, the Crown Land Management Act 2009 and the Wilderness Protection Act 1992. Together, they cover a total land area of 211,387.48 km2 (81,617.16 sq mi) or 21.5% of the state's area.

Australia's National Reserve System (NRS) is a network of more than 10,000 Commonwealth plus state and territory protected areas which, in combination, on a national scale, protect more than 137 million hectares, greater than 17% of the continent, of unique biodiversity and most significant ecological landscapes for future generations. The aim of the NRS is protect the diversity of all native landscapes, flora and fauna across Australia through strategic habitat protection. It consists of public, indigenous and privately protected areas of land and inland freshwaters.