The train began operating in 1877, jointly owned and operated by the Victorian Railways and the South Australian Railways, both operated by the respective colonial and later state governments. The train was originally known as the Intercolonial Express, and it was the first through train between Australian capital cities. The name The Overland was adopted in June 1926. Locomotives and crews were originally changed at Serviceton, a station on the Victorian side of the South Australian border built for the purpose.
The train used to operate every night in each direction, having when the service commenced the first sleeping cars to run in Victoria, but since 2006 has operated on a daytime schedule, with it now leaving Adelaide on Mondays, Wednesdays, and Fridays, and Melbourne on Tuesdays, Thursdays, and Saturdays. The service was transferred from the government railways to private operator Great Southern Rail in 1997.
The Overland includes a vehicle for carrying passengers' cars, a service known as "Motorail".
The broad gauge (5' 3"63 inches
1,600.199 mm) Victorian and South Australian railways connected at three places, Mt. Gambier, Serviceton, and Pinaroo, with the line via Serviceton being the main line and most direct route. The Overland has always travelled via Serviceton, except when the main line was blocked.
There are also three routes between Melbourne and Ararat, on the line to Serviceton. The original main line to Adelaide went via Bacchus Marsh and Ballarat. An alternative route is via Geelong to Ballarat, which was the original line to Ballarat. The last line to be built was a line across the plains between Geelong and Ararat. This route has easier grades than the routes via Ballarat, but served no major towns between Geelong and Ararat.
The Overland normally travelled via Ballarat, although its route between Ballarat and Melbourne varied between the lines via Bacchus Marsh and via North Geelong. However, when the line between Melbourne and Adelaide was converted to standard gauge in 1995, it was the line across the plains between Geelong and Ararat which was chosen for conversion. This meant that The Overland now travels on that route, bypassing Ballarat, but serving Geelong's North Shore station instead.
The old Adelaide terminal of The Overland was Adelaide's main station, but since being converted to standard gauge, Parklands, formerly known as Keswick, on the outskirts of the CBD, has been used instead.
The Melbourne terminal of The Overland has always been Southern Cross station (formerly known as Spencer Street).
The current length of the journey is 828km514.494 miles