Joanna is a locality in the Australian state of South Australia located in the state's south-east within the state’s Limestone Coast region about 325 kilometres (202 mi) south east of the state capital of Adelaide, about 19.5 kilometres (12.1 mi) south-east of the municipal seat of Naracoorte.
Joanna started as a private subdivision. Boundaries were created in April 2001 for the “long established name” which is derived from the cadastral unit of the Hundred of Joanna which was named in 1862 after the daughter of Dominick Daly, the then Governor of South Australia.
The majority land use within the locality is primary production. The locality includes land proclaimed for conservation purposes as the Naracoorte Caves National Park.
Joanna shares a single CFS brigade with the neighbouring locality of Wrattonbully.
Joanna is located within the federal Division of Barker, the state electoral district of MacKillop, and the local government area of the Naracoorte Lucindale Council.