The Scottish Parliament (Scottish Gaelic: Prlamaid na h-Alba [parlmt n halap]; Scots: Scots Pairlament) is the devolved, unicameral legislature of Scotland. Located in the Holyrood area of the capital city, Edinburgh, it is frequently referred to by the metonym Holyrood. The Parliament is a democratically elected body comprising 129 members known as Members of the Scottish Parliament (MSPs), elected for five-year terms under the additional member system: 73 MSPs represent individual geographical constituencies elected by the plurality (first-past-the-post) system, while a further 56 are returned as list members from eight additional member regions. Each region elects seven party-list MSPs. Each region elects 15 to 17 MSPs in total. The most recent general election to the Parliament was held on 6 May 2021, with the Scottish National Party winning a plurality.

The original Parliament of Scotland was the national legislature of the independent Kingdom of Scotland, and existed from the early 13th century until the Kingdom of Scotland merged with the Kingdom of England under the Acts of Union 1707 to form the Kingdom of Great Britain. As a consequence, both the Parliament of Scotland and the Parliament of England ceased to exist, and the Parliament of Great Britain, which sat at Westminster in London, was formed.

Following a referendum in 1997, in which the Scottish electorate voted for devolution, the powers of the devolved legislature were specified by the Scotland Act 1998. The Act delineates the legislative competence of the Parliament the areas in which it can make laws by explicitly specifying powers that are "reserved" to the Parliament of the United Kingdom. The Scottish Parliament has the power to legislate in all areas that are not explicitly reserved to Westminster. The UK Parliament retains the ability to amend the terms of reference of the Scottish Parliament, and can extend or reduce the areas in which it can make laws. The first meeting of the new Parliament took place on 12 May 1999.The legislative competence of the Scottish Parliament has been amended numerous times since then. The Scotland Act 2012 and Scotland Act 2016 expanded the Parliament's powers, especially over taxation and welfare. The United Kingdom Internal Market Act 2020 seeks to restrict the exercise of devolved competences both legally and practically. It aims to avoid regulatory divergence by the devolved nations following Brexit and, while not particularly changing devolved competences on paper, restricts the way that devolved competences operate in practice by imposing requirements of market non-discrimination and mutual recognition. Its effect is to undermine the freedom of action, regulatory competence and authority of the Parliament, limiting its ability to make different economic or social choices to those made by Westminster.

Devolution is the statutory delegation of powers from the central government of a sovereign state to govern at a subnational level, such as a regional or local level. It is a form of administrative decentralization. Devolved territories have the power to make legislation relevant to the area, thus granting them a higher level of autonomy.Devolution differs from federalism in that the devolved powers of the subnational authority may be temporary and are reversible, ultimately residing with the central government. Thus, the state remains de jure unitary. Legislation creating devolved parliaments or assemblies can be repealed or amended by central government in the same way as any statute. In federal systems, by contrast, sub-unit government is guaranteed in the constitution, so the powers of the sub-units cannot be withdrawn unilaterally by the central government (i.e. not through the process of constitutional amendment). The sub-units therefore have a lower degree of protection under devolution than under federalism.