Barmera is a town in the Riverland region of South Australia. It is on the Sturt Highway A20, 220 kilometres north-east of Adelaide, the capital of the state of South Australia. It is primarily an agricultural and viticultural town and is located on Lake Bonney Riverland, a freshwater lake.

The Division of Barker is an Australian electoral division in the south-east of South Australia. The division was established on 2 October 1903, when South Australia's original single multi-member division was split into seven single-member divisions. It is named for Collet Barker, an early explorer of the region at the mouth of the Murray River. The 63,886 km² seat currently stretches from Morgan in the north to Port MacDonnell in the south, taking in the Murray Mallee, the Riverland, the Murraylands and most of the Barossa Valley, and includes the towns of Barmera, Berri, Bordertown, Coonawarra, Keith, Kingston SE, Loxton, Lucindale, Mannum, Millicent, Mount Gambier, Murray Bridge, Naracoorte, Penola, Renmark, Robe, Tailem Bend, Waikerie, and parts of Nuriootpa and Tanunda.