Before the Act of Union 1707, the barons of the sheriffdom or shire of Dumfries (also called Nithsdale) and the stewartry of Annandale elected commissioners to represent them in the unicameral Parliament of Scotland and in the Convention of Estates. The number of commissioners was increased from two to four in 1690.
After 1708, Dumfriesshire returned one member to the House of Commons of Great Britain and later to the House of Commons of the United Kingdom..