;Summary of results A candidate fielded by the Labour Party has won the seat since 1987. Prior to that the political division for Westminster purposes voted for the Conservative and Unionist candidate, ahead of all other candidates by single preference, at each Westminster election from and including 1918. Prior to that the electorates' single-most preferred candidate in simple voting was that of the Liberal Party, except in 1900 when a Liberal Unionist was returned. The 2015 result gave the seat the 23rd-smallest majority of Labour's 232 seats by percentage of majority. In the 2017 general election, Ian Murray received the highest voteshare of any Scottish candidate. It was also one of only two constituencies in Scotland where the winning candidate received a majority of the votes cast. ;Recent opposition candidates' performance At the 2015 general election three of the seven parties' candidates standing retained their deposits, their votes exceeding 5%. Those doing so and not winning were SNP – 33.8% of the vote and Conservative – 17.5% of the vote. At this election the SNP increased their share of the vote by over 26%, coming a close second to Ian Murray of the Labour Party. The Liberal Democrat candidate of 2005 fell within 0.9% of a winning majority. The Liberal Democrats' swing nationally was -15.2% swing in 2015. The swing in this seat against the party was however -30.3% resulting in the loss of their deposit, a fate not sustained by either of the party's two formative parties in the seat since 1970. ;Turnout Turnout has ranged between 81.1% in 1950 and 57.7% in 2001. ;2016 EU referendum In the 2016 referendumof membership of theEuropean Union, the constituency voted Remain by 77.8%. This was the tenth highest support for remain for a constituency.
Boundaries
When created in 1885, the Westminster constituency was partly a replacement for the Edinburgh constituency. The Redistribution of Seats Act 1885 provided that the constituency was to consist of the Municipal Wards of St. George, St. Cuthbert, and Newington. In 1918 the constituency consisted of the "Merchiston, Morningside, and Newington Municipal Wards of Edinburgh." In 2005, prior to the general election, Edinburgh South was one of six covering the City of Edinburgh council area. Five were entirely within the city council area. One, Edinburgh East and Musselburgh, straddled the boundary with the East Lothian council area, to take in Musselburgh. For the 2005 election, the constituency was enlarged to include areas from the former Edinburgh Pentlands constituency, and became one of five constituencies covering the city area, all entirely within that area. The constituency covers a southern portion of the city area, and is predominantly suburban. In terms of wards used in elections to the City of Edinburgh Council 1999 to 2007, it includes the wards of Alnwickhill, Fairmilehead, Gilmerton, Kaimes, Marchmont, Merchiston, Moredun, Little France, Newington, North Morningside and the Grange, Sciennes, and South Morningside. These wards were replaced with new wards in 2007, as a result of the Local Governance Act 2004. The constituency therefore contains almost no electoral wards in its entirety. Those within its boundaries are Southside/Newington, Meadows/Morningside, a handful of streets from the extreme north-east of Fountainbridge/Craiglockhart ward, Colinton/Fairmilehead, and Liberton/Gilmerton.
