The Ely and St Ives Railway was a railway company that opened a line between those places (in Cambridgeshire, England) in 1878. It was an extension of the privately promoted Ely, Haddenham & Sutton Railway that had opened in 1866. It was a standard gauge single track. The line was worked by the neighbouring Great Eastern Railway but it was never profitable. The development of road transport services in the 1920s caused a steep decline in use of the line, and the passenger service was withdrawn in 1931. A goods service continued, but the line closed completely in 1964. No railway activity takes place on the route now.

The Eastern Counties Railway opened its line from Cambridge to Ely in 1845. The Ely and Huntingdon Railway was authorised in 1845; it was to build from east to west through St Ives, but it was unable to raise sufficient money to build the whole of its line. Instead it opened only between St Ives and a station named Huntingdon, that was actually in Godmanchester, east of the River Great Ouse. The opening date was 17 August 1847, and the Eastern Counties Railway between Cambridge and St Ives was opened on the same day.^{[page needed]}

The East Anglian Railway soon acquired the Ely and Huntingdon Railway, but it did not consider that progressing the completion of the Ely and Huntingdon scheme was worthwhile, and it allowed the powers to lapse. In August 1862 the Eastern Counties Railway merged with other lines to form the Great Eastern Railway; this heralded a change of policy in that the Great Eastern Railway decided to encourage local schemes for connecting and feeder railways.^{[page needed]}

Accordingly in the Autumn of 1863 two prominent landowners, Oliver Claude Pell of Wilburton and Frederick Camps of Haddenham, generated enough support from other landowners in the area to consider building a line linking Ely and Sutton, about a third of the extent of the unbuilt Ely to St Ives line. The route was planned at first to be direct via Witchford, but Pell and Camps insisted on a route further south to serve their estates and the planned route of the line was altered accordingly. This had the incidental benefit of aligning the route on lower ground throughout, with easy gradients. The line was to be known as the Ely, Haddenham and Sutton Railway.^{[page needed][page needed]}

The Great Eastern Railway considered assisting the promoters of the Ely, Haddenham and Sutton Railway, but they were sceptical about its potential profitability. Now the local company proposed an extension from Sutton to Somersham on the St Ives to March line and this changed the GER position, as they saw this as a threat to their strategic intentions, potentially facilitating an incursion by the Great Northern Railway.^{[page needed]}

The GER were therefore anxious to dissuade the local company from the Somersham extension, and they offered to support the local scheme to the extent of one third of the required capital if they would drop it. This was agreed to, and the Ely, Haddenham and Sutton Railway got its Act of Parliament on 23 June 1864. Share capital was £36,000 with borrowing powers of £12,000. The GER was authorised to subscribe £12,000, and the EH&SR had running powers to enter Ely station.^{[page needed][page needed][page needed][page needed][page needed]}

A construction contract was let to W S Simpson of Ely in the sum of £48,000; early in 1866 the EH&SR agreed a working arrangement with the GER, for 50% of gross receipts.

Captain Tyler made an inspection of the line for the Board of Trade on 28 March 1866. He identified numerous shortcomings, and permission for opening to passenger trains was refused. Urgent improvements were put in hand, and Tyler authorised opening on 7 July 1866 subject to completion of certain final rectification. The formal opening of the line took place on 6 April 1866, and the full public opening was on 16 April 1866.^{[page needed][page needed][page needed][page needed]}