The Marshlink line is a railway line in South East England. It runs from Ashford, Kent via Romney Marsh, Rye and the Ore Tunnel to Hastings where it connects to the East Coastway line towards Eastbourne. Services are provided by Southern.
The line was constructed by the South Eastern Railway (SER) in the late 1840s, and was considered politically important. The SER clashed with the rival London, Brighton and South Coast Railway, leading to disputes over the route, planning and operation. After delays, the line opened in February 1851, followed by branch lines to Rye Harbour in 1854, Dungeness in 1881 and New Romney in 1884. The line struggled to be profitable and it seemed likely that it would close as recommended by the Beeching Report. All branch lines were closed to passengers by 1967 but the main line was kept open because of poor road connections in the area, and the branch to Dungeness remained open for freight. Though the line has been partially single-tracked, and was slow to be modernised, it has survived into the 21st century.
The Marshlink line is one of the few in South East England that has not been electrified, despite regular proposals to do so, and uses the British Rail Class 171 diesel rolling stock.