Lake Grace South, part of the Lake Grace System, is a wetland located in the Great Southern region of Western Australia.

Situated in the Shire of Kent, the lake is part of the Western Mallee subregion of the Mallee region.

[2] It has an area of about 56 square kilometres (22 sq mi).

It is one of four lakes in the area comprising a DIWA-listed wetland of national importance.

[3] Lake Grace South is part of the Chinocup Nature Reserve, gazetted on 20 January 1967 and has a size of 198.25 square kilometres (76.54 sq mi).