Scottish Parliament constituencies and regions were first used in 1999, in the first general election of the Scottish Parliament (Holyrood), created by the Scotland Act 1998.
The parliament has 73 constituencies, each electing one Member of the Scottish Parliament (MSP) by the plurality (first past the post) system of election, and eight additional member regions, each electing seven additional MSPs.
Each region is a group of constituencies, and the D'Hondt method of allocating additional member seats from party lists is used to produce a form of proportional representation for each region.
The total number of parliamentary seats is 129. For lists of MSPs, see Member of the Scottish Parliament.
Boundaries of Holyrood and British House of Commons (Westminster) constituencies are subject to review by the Boundary Commission for Scotland, and prior to the Scottish Parliament (Constituencies) Act 2004 reviews of Scottish Westminster constituencies would have been also reviews of Holyrood constituencies.