The Upper Darling Range railway (also known as the Upper Darling Range branch) was a branch railway from Midland Junction, Western Australia, that rose up the southern side of the Helena Valley and on to the Darling Scarp via the Kalamunda Zig Zag.

At the time of construction it was the only section of railway in Western Australia to have had a zig zag formation.

It ran from Midland Junction railway station through to the Darling Ranges and up into Kalamunda.

[2][3] On 1 July 1903, the line was taken over by the Western Australian Government Railways and became known as the Upper Darling Range branch.

The line was formally closed by the Railways (Upper Darling Range) Discontinuance Act 1950; it was dismantled in 1952.