The state electorate of Polwarth has an approximate area of 13,000 km².

It is comprised of 166 suburbs including Aire Valley, Aireys Inlet, Alvie, Anglesea, Apollo Bay, Ayrford, Balintore, Bambra, Bannockburn, Barongarook, Barongarook West, Barramunga, Barunah Park, Barunah Plains, Beeac, Benwerrin, Berrybank, Big Hill, Boonah, Boorcan, Bostocks Creek, Bradvale, Brucknell, Buckley and Bullaharre plus parts of another 12 suburbs.

It is comprised of the localities of Barwon Downs, Beech Forest, Birregurra, Bookaar, Carlisle River, Cooriemungle, Darlington, Derrinallum, Dundonnell, Hexham, Inverleigh, Irrewillipe, Leslie Manor, Lismore, Mortlake, Ombersley, Princetown, Rokewood, Shelford, Simpson, Vite Vite North, Werneth and Winchelsea plus parts of 3 localities including Nerrin Nerrin, Skipton and Woorndoo.

It is comprised of the councils of Colac Otway Shire and Corangamite Shire plus parts of Golden Plains Shire, Moyne Shire and Surf Coast Shire.

It is surrounded by the state electorates of Buninyong, Geelong, Lara, Lowan, Ripon, South Barwon and South-west Coast.

It is comprised of parts of the federal electorates of Corangamite and Wannon.