Mayo is named after Helen Mayo 1878–1967, co-founder of the Mothers' and Babies' Health Association in and first woman elected to a University Council of Australia.
Mayo covers an area of approximately 9 315 sq km from Springton in the North to Goolwa in the South. It includes the Adelaide Hills, Fleurieu Peninsula and Kangaroo Island. The country towns include Birdwood, Bridgewater, Crafers, Echunga, Gumeracha, Hahndorf, Langhorne Creek, Lobethal, Macclesfield, Mount Barker, Myponga, Oakbank, Stirling, Strathalbyn, Victor Harbor, Woodside and Yankalilla.
The Mayo electorate is renowned for its tourist attractions, dairying, beef, sheep, apples, pears, cherries, smallgoods, Kanmantoo copper mines, Jupiter Creek goldfields, forestry, natural spring water, wine, cereals and the army barracks at Woodside.