The Greenock and Wemyss Bay Railway was a railway owned by the Caledonian Railway, providing services between Greenock and Wemyss Bay.
In 1841 the Glasgow, Paisley and Greenock Railway opened its line. At the time the River Clyde was heavily used by boats, but it was impassable for sea-going vessels, involving transshipment at Greenock, and transfer of passengers.
The company's promoters anticipated the carriage of goods from the industries of Greenock, and as well as competing for the transshipment traffic. However their terminal station at Greenock was at Cathcart Street, some distance from the Custom House Quay and not directly connected to any shipping berth.
Nonetheless substantial traffic built up, and in particular passenger traffic grew considerably. The traffic to resort locations on the Firth of Clyde and other coastal places, was especially encouraging, and the steamer trade became lucrative.
The throughout journey time—rail and ship—was considered critical. As a pioneer railway, the Greenock company had not given thought to this, but slowly the disadvantage of the Greenock station became more prominent. The walk from the railway station to the Quay was through squalid streets, and the steamer transit to the lower Clyde involved a circuit round Kempock Point and Cloch Point to reach the seaway.
In 1851 the Glasgow, Paisley and Greenock Railway was absorbed by the dominant Caledonian Railway.
Rothesay assumed dominance as the resort destination of choice, and many businesspeople in Glasgow kept residences there, travelling weekly to their places of business in the City. Promoters saw that a railway link to Wemyss Bay would be ideal, as the pier they lay directly opposite Rothesay, and on 17 July 1862 they obtained Parliamentary authorisation for the Greenock and Wemyss Bay Railway. Their line was to form a junction with the Greenock line a short distance west of Port Glasgow station; it would then climb and run round to the south of Greenock, then following the valley of the Spango Burn to a station on the hillside above Inverkip, then turning south to a pier station at Wemyss Bay. Lands were acquired speculatively at Upper Greenock for industrial development.
The line was opened to traffic on 15 May 1865.
The railway was worked by the Caledonian Railway, which operated through passenger trains from the Bridge Street station in Glasgow. An independent Wemyss Bay Steamboat Company Limited operated steamers in connection with the trains. However this meant that the railway company was dependent on two other concerns for the conduct of its business, and reliability problems on the railway and in operating the steamers led to a poor reputation. After four years, the Steamboat Company failed (in 1869), and the Rothesay connections, on which the Wemyss Bay Railway relied, were made by other steamer operators as part of their wider network of routes.