Ochil and South Perthshire was a county constituency of the House of Commons of the Parliament of the United Kingdom. It elected one Member of Parliament (MP) by the first-past-the-post system of election.

The constituency was created for the 2005 general election as a result of the Fifth Review of the Boundary Commission for Scotland. It has been represented since 2019 by John Nicolson of the Scottish National Party (SNP).

The seat was abolished prior to the 2024 general election and replaced by parts of five other constituencies.

The Ochil and South Perthshire constituency covered the rural south of the Perth and Kinross council area south of the River Tay, running down through the Ochil Hills into the more industrial Clackmannanshire council area to the south. It was an affluent constituency.

Agriculture and tourism formed an important part of the local economy in the north of the constituency in southern Perth and Kinross-shire, housing affluent resort towns such as Auchterarder, Crieff and Kinross. Clackmannanshire is better known for its light industry and breweries dotted along the course of the River Forth and its northern tributary streams.

The Ochil and South Perthshire constituency was formed from elements of the old Ochil and Perth constituencies. Perth was traditionally a strong area of support for the Conservative Party until the party's wipeout in Scotland at the 1997 general election, from then onwards; the area usually voted SNP. Ochil covered the counties of Kinross-shire and Clackmannanshire, alongside some of the more industrialised parts of Stirlingshire, traditionally an SNP-Labour marginal. When Ochil and South Perthshire was first formed, it was thought of as an SNP-Labour marginal; however, the SNP failed to win the constituency when it was created in 2005, and at the subsequent general election in 2010. Tasmina Ahmed-Sheikh gained the seat from Gordon Banks of the Labour Party in a landslide victory across Scotland at the 2015 general election as they won 56 of Scotland's 59 parliamentary seats. At the 2017 general election, Ahmed-Sheikh lost the constituency to Luke Graham of the Conservative Party, and in 2019, Graham lost the seat to John Nicolson, former SNP MP for East Dunbartonshire.

At the 2017 local election, all wards in southern Perth and Kinross-shire voted Conservative by a good margin. The result in Clackmannanshire was mixed, with the SNP forming the largest party across the county as a whole but missing out to the Conservatives in Dollar to the north-east of the council area and missing out to Labour in northern Alloa. The Conservatives came first across Ochil and South Perthshire on the whole, with the SNP in second place.