The Clydesdale Junction Railway company was formed to build a railway connecting Motherwell and Hamilton with Glasgow, in Scotland.
Conceived for local journeys, it was used by the main line Caledonian Railway to get access to Glasgow, and was soon taken over by the larger company. The route formed an alternative main line to Glasgow for the Caledonian, and eventually was the dominant route to the city.
Although the Company was taken over before completion of its line, its short route remains in heavy use today as part of the West Coast Main Line, carrying heavy inter-city and suburban traffic, and some freight.
The Clydesdale Junction Railway was promoted to connect Hamilton and Motherwell with the southern side of Glasgow, by joining the eastern end of the Polloc and Govan Railway, and forming a short line from it to a Glasgow terminal.
It obtained an authorising Act of Parliament on 31 July 1845, with capital of £330,000. At Motherwell it linked with the Wishaw and Coltness Railway at a point a little east of the present-day station and junction.
The Caledonian Railway obtained its own authorising Act in the same session, on the same day. The Caledonian had struggled for a long time to get approval for its main line linking Glasgow and Edinburgh with Carlisle and the burgeoning English railway network. Contemplating a long main line through relatively unpopulated terrain, the Caledonian had sought to economise by routing its line into Glasgow over two former "coal railways": the Wishaw and Coltness Railway, and the Glasgow, Garnkirk and Coatbridge Railway, successor to the Garnkirk and Glasgow Railway. It was to lease those lines and they were to be modernised: they were partly horse-operated with primitive track on stone block sleepers, and had used a track gauge that had become common among Scottish mineral lines but was incompatible with the standard gauge used by the emerging national railway network.
The route into Glasgow traced a broad northward sweep from Motherwell by way of Gartsherrie and Garnkirk, to a cramped and inconveniently located terminal at Townhead in Glasgow. The Caledonian now realised that the Clydesdale Junction line would give them an alternative, possibly superior, route to the City. In a quick submission, the Caledonian obtained Parliamentary authorisation to acquire the Clydesdale Junction and the Polloc and Govan by Act of 18 August 1845.