The Maryport & Carlisle Railway (M&CR) was an English railway company formed in 1836 which built and operated a small but eventually highly profitable railway to connect Maryport and Carlisle in Cumbria, England. There were many small collieries in the area and efficient access to the harbour at Maryport was important.
The western end, connecting the majority of the collieries to Maryport opened in 1840 and the line was completed throughout to Carlisle in 1845. The considerable resources of coal, and later iron ore, carried by the railway made it especially profitable, and this was redoubled at the height of the iron and steel processing industries around Workington. Branch lines were opened to connect further collieries.
After 1918 the industries on which the line was dependent declined steeply, and the railway declined accordingly; the branch lines closed, but the original main line remains open and forms part of the Cumbrian Coast Line between Carlisle and Barrow in Furness.
Coal had been mined in West Cumberland since the seventeenth century. Most of the coalfield was south of Maryport, and enjoyed easy access to harbours at Workington and Whitehaven, through which the coal could be shipped. Useful coal deposits were known to exist east of Maryport, as far as Aspatria, but it was difficult to work them profitably, for want of practicable roads. Early in the eighteenth century new collieries started work and in 1749 Humphrey Senhouse lord of the manor constructed a harbour and founded the town of Maryport at the mouth of the River Ellen. His son (also Humphrey Senhouse) was involved in the 1790s in the promotion of a canal from Newcastle upon Tyne to Maryport, but the project lapsed in the financial crisis of 1797. When thoughts turned again in the 1820s to improving the links from Newcastle to Cumberland a Newcastle -Carlisle canal was rejected in favour of a railway. Speaking at an 1834 dinner marking the inauguration of gas lighting in Maryport Sir Humphrey Fleming Senhouse "alluded to the situation of Maryport as an inlet for an important district of the country, and strongly urged the importance of a railway to join that now in progress from Carlisle to Newcastle".
The suggestion was taken up, and in August 1836 George Stephenson visited Maryport, and in October 1836 reported the results of a survey carried out for him, which showed that such a railway was practicable and potentially profitable. Dividends of 18% were promised, and a prospectus was issued; the Maryport and Carlisle Railway obtained its authorising Act of Parliament on 12 July 1837. The Act asserted that the line "would facilitate the communication between the Continent of Europe and Ireland and the Western Coast of England by forming in conjunction with the Newcastle-upon-Tyne and Carlisle Railway and the Brandlings Junction Railway, one complete and continuous line of communication from the German Ocean to the Irish Sea". The authorised capital was £180,000.