Cunninghame South (Gaelic: Coineagan a Deas) is a county constituency of the Scottish Parliament covering part of the council areas of North Ayrshire and East Ayrshire. Under the additional-member electoral system used for elections to the Scottish Parliament, it elects one Member of the Scottish Parliament (MSP) by the first past the post method of election. It is also one of ten constituencies in the West Scotland electoral region, which elects seven additional members, in addition to the ten constituency MSPs, to produce a form of proportional representation for the region as a whole.
The seat has been held by Ruth Maguire of the Scottish National Party (SNP) since the 2016 Scottish Parliament election.
The other nine constituencies of the West Scotland region are: Clydebank and Milngavie, Cunninghame North, Dumbarton, Eastwood, Inverclyde, Paisley, Renfrewshire North and Cardonald, Renfrewshire West and Levern Valley, and Strathkelvin and Bearsden. The region covers the whole of the council areas of East Dunbartonshire, East Renfrewshire, Inverclyde, North Ayrshire, Renfrewshire, and West Dunbartonshire; and parts of the council areas of Argyll and Bute, East Ayrshire, and Glasgow.
Prior to the first periodic review of Scottish Parliament boundaries in 2011, Cunninghame South was placed within the South of Scotland region. The other eight constituencies in this region during this period were: Ayr, Carrick, Cumnock and Doon Valley, Clydesdale, Dumfries, East Lothian, Galloway and Upper Nithsdale, Roxburgh and Berwickshire, and Tweeddale, Ettrick and Lauderdale.
Cunninghame South was created at the same time as the Scottish Parliament, in 1999, using the name and boundaries of an existing UK Parliament constituency. In 2005 Scottish constituencies for the UK House of Commons were mostly replaced with new constituencies, causing UK and Scottish parliamentary constituencies to no longer correspond. Following their First Periodic review into constituencies to the Scottish Parliament in time for the 2011 Scottish Parliament election, the Boundary Commission for Scotland altered the boundaries of the constituency. It was further altered by the Second Periodic Review of Scottish Parliament Boundaries in 2025 ahead of the 2026 Scottish Parliament election, with the villages of Dunlop and Stewarton being added from the Kilmarnock and Irvine Valley constituency in order to address differences in electorate size between the two seats.
The constituency is one of two in North Ayrshire, with the rest of the council area being covered by the Cunninghame North constituency. Following the 2025 review, it also includes parts of East Ayrshire; the remainder of East Ayrshire is covered by the Carrick, Cumnock and Doon Valley and Kilmarnock and Irvine Valley constituencies.
The electoral wards of East Ayrshire Council and North Ayrshire Council used in the current creation of Cunninghame South are:
The Cunninghame South constituency occupies the southern portion of the North Ayrshire Council area, covering the towns of Kilwinning, Stevenston and Irvine. The part of the constituency lying in East Ayrshire is mostly made up of farmlands, with the historic town of Stewarton lying directly north of Kilmarnock along the Annick Water.
The area has traditionally been represented by the Labour Party, with Labour continuously representing the Central Ayrshire and Cunninghame South constituencies at the British Parliament from 1959 until 2015 - when the constituency of Central Ayrshire was won by the Scottish National Party on a 27.7% swing from Labour to SNP. In the Scottish Parliament Cunninghame South was represented by the Labour Party from the establishment of the Scottish Parliament in 1999 until 2011, when the seat was gained by the SNP on a 9.9% swing.