The Deeside Railway was a passenger and goods railway between Aberdeen and Ballater in Aberdeenshire, Scotland. Opening in 1853 to Banchory, an extension reached Aboyne in 1859. A separate company, the Aboyne & Braemar Railway, built an extension to Ballater and this opened in 1866. By 1855 there were five services a day over the 43 1⁄4-mile (69.6 km) long line, taking between 1 hour 50 minutes and 2 1⁄2 hours. The line was used by the Royal Train for travel to and from Balmoral Castle from 1853 and a special 'Messenger Train' ran daily when the Royal Family was in residence.
The railways were absorbed by the Great North of Scotland Railway on 1 August 1875 for the Deeside Railway and 31 January 1876 for the Aboyne & Braemar. The line became part of the London and North Eastern Railway in 1923, and part of British Railways when nationalised in 1948. The line was closed, to Ballater on 18 July 1966 and to Culter on 2 January 1967.
A railway to serve Deeside was first suggested in 1845. A 16-mile (26 km) long line to Banchory was estimated to cost £95,000, or £220,000 to reach Aboyne, a distance of 30 miles (48 km). This was authorised on 16 July 1846, but it was decided to wait for the Aberdeen Railway to first open. Shareholders wanted their money back when the railway mania bubble burst, but it survived because the Aberdeen Railway bought a large number of shares. Interest was restored after Prince Albert purchased Balmoral Castle, to which the Royal Family made their first visit in 1848, and the Aberdeen Railway was able to sell their shares. Investors were still hard to find, but by limiting the railway to a line between Ferryhill, in Aberdeen, and Banchory the Deeside Railway was able to apply to Parliament for permission in 1852. Permission was granted, and the railway opened on 7 September 1853.