Finniss is a single-member electoral district for the South Australian House of Assembly.

It covers a 1,004 km2 (388 sq mi) regional area which includes the localities of Back Valley, Currency Creek, Encounter Bay, Finniss, Goolwa, Goolwa Beach, Goolwa North, Goolwa South, Hayborough, Hindmarsh Island, Hindmarsh Tiers, Hindmarsh Valley, Lower Inman Valley, McCracken, Middleton, Mosquito Hill, Mount Compass, Mount Observation, Mundoo Island, Nangkita, Port Elliot, Tooperang, and Victor Harbor; as well as parts of Inman Valley and Waitpinga.

Brown retired at the 2006 election, and was succeeded by Liberal candidate Michael Pengilly, who held off a concerted attempt by the SA Nationals to take the seat.

David Basham retained the seat for the Liberals, despite a spirited challenge from SA-BEST.

Indeed, SA-BEST's showing in Finniss was strong enough to make the seat marginal for the first time in its current configuration.