The Royston to Thornhill line was a Midland Railway venture constructed in West Yorkshire, England, that had the intent to allow trains to travel from Sheffield to Bradford without going through Leeds.

The line was promoted by the Midland Railway with a view to shortening the distance needed to travel from London St Pancras to Bradford,[note 1] and also to allow the Midland to make inroads into the Huddersfield, Halifax and Dewsbury areas.

[10] The only major structure on the single-track Mirfield to Huddersfield Newtown Branch, was a 15-arch viaduct across the River Colne at Bradley.

[11] Had the scheme been carried out to the full plans, a new line would have been constructed along the Spen Valley, and a tunnel would have been required under Bradford for a length of 5,000 yards (4,600 m), which would have started south of Bradford and emerged at the Midland Line from Forster Square[note 2] just 150 yards (140 m) north of the platform ends at Forster Square.

[13] One of the conditions attached to the 1898 bill was that the Midland Railway were legally responsible protect the water rights for a water-powered mill in the Ripley area of Bradford.

[16] The whole project was shelved at the start of the First World War, and never resurrected, with the scheme being formally abandoned in November 1919.

[22] Middlestown and Crigglestone East stations had goods yards, and they were built with two platforms each, both of these aligned along the main running lines.

[25] The bulk of the line was closed in 1968, though the section between Thornhill and Crigglestone Viaduct was kept open to provide materials for the building of the M1 at the eastern end.

[26] The eastern section of line through Notton is now bridleway and cyclepath, connecting with the Trans Pennine Trail in Royston.

[35] This produced a shorter branch of 1 mile 286 yards (1.871 km) between Red Doles and Newtown.