The Glenelg Highway is a 301 kilometre highway in south-eastern Australia, linking Mount Gambier with Ballarat. Most of the highway is located within the Western part of the state of Victoria; except for a short, 15 km stretch from the South Australia/Victoria state border near Ardno to Glenburnie (6 km east of central Mount Gambier) is located in South Australia. Some maps identify the South Australian stretch as Casterton Road. Major towns along its route include Casterton, Coleraine and Hamilton.