South Eastern Freeway is a 73 km (45 mi) freeway in South Australia (SA). It is a part of the National Highway network linking the state capital cities of Adelaide, SA, and Melbourne, Victoria, and is signed as route M1. It carries traffic over the Adelaide Hills between Adelaide and the River Murray, near Murray Bridge, where it is connected via the Swanport Bridge to the Dukes Highway, which is the main road route to Victoria.

The National Highway is a system of roads connecting all mainland states and territories of Australia, and is the major network of highways and motorways connecting Australia's capital cities and major regional centres.