Wolseley is a small South Australian town near the Victorian border. It is five kilometres south of the Dukes Highway and 13 kilometres east of Bordertown. It was first proclaimed a town in 1884.
A broad (1600 mm) gauge railway was opened to Adelaide and Melbourne in 1886. Some years later the Millicent – Mount Gambier narrow (1067 mm) gauge railway was extended to Wolseley, creating a break-of-gauge rail junction. In the 1950s the break-of-gauge was abolished by the conversion of the Mount Gambier line to broad gauge. The line to Mount Gambier has been out of use since the conversion of the Adelaide – Melbourne line to standard (1435 mm) gauge in 1995, pending possible conversion to standard gauge.
Early in World War II, No. 12 Inland Aircraft Fuel Depot was established at Wolseley, with an initial capacity of 280,000 gallons in three tanks camouflaged to look like farm buildings. The depot started operations in 1942 and three additional tanks were added later. It was disbanded on June 14, 1944.
Wolseley is in the Tatiara District Council, the state electoral district of MacKillop and the federal Division of Barker.