The Shire of Plantagenet is a local government area in the Great Southern region of Western Australia, managed from the town of Mount Barker, 360 kilometres (224 mi) south of Perth and 50 kilometres (31 mi) north of Albany. The shire covers an area of 4,792 square kilometres (1,850 sq mi) and includes the communities of Narrikup, Rocky Gully, Kendenup and Porongurup.

The Great Southern region is one of the nine regions of Western Australia, as defined by the Regional Development Commissions Act 1993, for the purposes of economic development. It is a section of the larger south coast of Western Australia and neighbouring agricultural regions.