The federal electorate of Lyons has an approximate area of 33,000 km².

It is comprised of 249 suburbs including Acacia Hills, Akaroa, Andover, Antill Ponds, Apsley, Baden, Badger Head, Bagdad, Bakers Beach, Barrington, Beaconsfield, Beaumaris, Beauty Point, Beulah, Bicheno, Binalong Bay, Birralee, Bishopsbourne, Black Hills, Blackwall, Blackwood Creek, Boomer Bay, Boyer, Bracknell and Bradys Lake plus parts of another 23 suburbs.

It is comprised of 61 localities including Ansons Bay, Arthurs Lake, Avoca, Ben Lomond, Bothwell, Bronte Park, Buckland, Butlers Gorge, Campbell Town, Central Plateau, Colebrook, Conara, Cranbrook, Cressy, Deddington, Douglas-apsley, Ellendale, Epping Forest, Fingal, Florentine, Frankford, Goshen, Gretna, Hamilton and Interlaken plus parts of another 10 localities.

It is comprised of the councils of Break O'day, Central Highlands, Derwent Valley, Glamorgan-spring Bay, Kentish, Meander Valley, Northern Midlands, Southern Midlands and Tasman plus parts of Brighton, Latrobe, Sorell and West Tamar.

It is comprised of parts of the Lyons state electorate.

It is surrounded by the federal electorates of Bass, Braddon, Denison and Franklin.