The state electorate of Barwon has an approximate area of 356,000 km².

It is comprised of the suburbs of Barringun, Beemunnel, Black Hollow, Curlew Waters, Euabalong West, Eulah Creek, Grawin Opal Fields, Harparary, Murrin Bridge, Pine Grove, Ravenswood, Red Hill, Snakes Plain, Sunset Strip and Turrawan plus parts of Derriwong.

It is comprised of 177 localities including Albert, Angledool, Armatree, Baan Baa, Babinda, Balladoran, Baradine, Bearbong, Biddon, Billeroy, Binnaway, Bobadah, Bogan, Bohena Creek, Bomera, Boolcarroll, Boona Mount, Bourbah, Bourke, Box Ridge, Breelong, Brewarrina, Broken Hill, Broughams Gate and Buddabadah plus parts of another 22 localities.

It is comprised of the councils of Bogan, Bourke, Brewarrina, Broken Hill, Central Darling, Cobar, Coonamble, Far West, Gilgandra, Lachlan, Narrabri, Walgett, Warren and Warrumbungle Shire.

It is surrounded by the state electorates of Cootamundra, Dubbo, Murray, Northern Tablelands, Orange, Stuart, Tamworth, Upper Hunter and Warrego.

It is comprised of parts of the Parkes federal electorate.