The Monkland Railways was a railway company formed in 1848 by the merger of three "coal railways" that had been built to serve coal and iron pits around Airdrie in Central Scotland, and connect them to canals for onward transport of the minerals. The newly formed company had a network stretching from Kirkintilloch to Causewayend, near Linlithgow. These coal railways had had mixed fortunes; the discovery of blackband ironstone and the development of the iron smelting industry around Coatbridge had led to phenomenal success, but hoped-for mineral discoveries in the moorland around Slamannan had been disappointing. The pioneering nature of the railways left them with a legacy of obsolete track and locomotives, and new, more modern, railways were being built around them.
The new company responded with connections to other lines, and to Bo'ness Harbour, and built new lines to Bathgate, but it was taken over by the Edinburgh and Glasgow Railway in 1865. Much of the network was dependent on proximity to pits and ironworks and as those became worked out or declined, the traffic on the network declined too, but the Coatbridge - Airdrie - Bathgate line remained open for passengers until 1956. The section east of Airdrie then closed, except for minor freight movements, but it was reopened in 2010, forming a through passenger route between Glasgow and Edinburgh via Airdrie and Bathgate. Part of the Bo'ness extension line was re-opened as the Bo'ness and Kinneil Railway, a heritage line. The remainder of the system has closed.
The North Monkland Railway was an independent line built to serve pits and quarries to the north of Airdrie beyond the reach of the Monkland Railways system. It opened in 1878 and was taken over in 1888, but it closed in the 1960s.
In 1826 the Monkland and Kirkintilloch Railway (M&KR) opened, with the primary purpose of carrying coal from the Monklands collieries, south of Airdrie to Kirkintilloch, from where it could continue to market in Glasgow and Edinburgh over the Forth and Clyde Canal. As a pioneering railway, it adopted a track gauge of 4 ft 6 in, and at first operated as a toll line, allowing independent hauliers to move wagons, using horse traction. It later acquired steam locomotives and ran trains itself. At first it was successful, and when the iron smelting industry became a huge success within the railway's area, it became even more successful.