Rail gauges in Australia display significant variations, which has presented an extremely difficult problem for rail transport on the Australian continent since the 19th century. As of 2022, there are 11,914 kilometres (7,403 mi) of narrow-gauge railways, 18,007 kilometres (11,189 mi) of standard gauge railways and 2,685 kilometres (1,668 mi) of broad gauge railways. In the 19th century, each of the colonies of Australia adopted their own gauges.

Rail transport in Australia is a component of the Australian transport system. It is to a large extent state-based, as each state largely has its own operations, with the interstate network being developed ever since Australia's federation in 1901. As of 2022, the Australian rail network consists of a total of 32,929 kilometres (20,461 mi) of track built to three major track gauges: 18,007 kilometres (11,189 mi) of standard gauge, 2,685 kilometres (1,668 mi) of broad gauge, and 11,914 kilometres (7,403 mi) of narrow gauge lines. Additionally, about 1,400 kilometres (870 mi) of 610 mm / 2 ft gauge lines support the sugar-cane industry. 3,488 kilometres (2,167 mi), around 11 percent of the Australian heavy railways network route-kilometres are electrified.