The Kwinana freight railway lines are a network of railways predominantly servicing the heavy industrial areas at Kwinana Beach south of Perth and to provide for the transport of freight servicing Fremantle Harbour, Kewdale Intermodal Facility and other freight destinations in Perth. While some lines were constructed in the 1900s, most of the network was constructed in the 1950s and 1960s.

The Mandurah line is a commuter railway and service on the Transperth network in Western Australia that runs from Perth south to the state's second largest city Mandurah. The service is operated by Transperth Train Operations, a division of the Public Transport Authority. The line is 70.1 kilometres (43.6 mi) long and has 12 stations. At its northern end, the line begins as a continuation of the Joondalup line at Perth Underground, and ends as a continuation of the Joondalup line at Elizabeth Quay. The first 1.3 kilometres (0.81 mi) of the line is underground, passing under the Perth central business district. The line surfaces and enters the median of the Kwinana Freeway just north of the Swan River. It continues south down the freeway's median for 30 kilometres (19 mi), before veering south-west towards Rockingham. The final stretch of the line goes south from Rockingham to Mandurah.