Cumberland Line

The T5 Cumberland Line is a suburban rail service operated by Sydney Trains in Sydney, New South Wales, Australia. It connects Schofields and Leppington stations in the western suburbs. Limited services extend from Schofields to Richmond. The line opened in 1996, following the construction of a 'Y-link' track between Harris Park and Merrylands stations. The intention of this link was to allow direct services to operate from the south west suburbs to Parramatta and Blacktown without requiring a change of trains at Granville. The line takes its name from the Cumberland Plain on which much of Greater Western Sydney was built.

Since 2013, the line has been numbered T5 and is coloured magenta on maps and wayfinding information.

Since 2025, the NSW Government has provided preliminarily designs for an expansion of the line dubbed the New Cumberland Line including an underground corridor preservation in Parramatta and an extension of the line to Epping similar to the former Parramatta Rail Link project that was shelved in 2003. The Albanese Government provided investment for a preliminary business case.