Ayrshire was a county constituency of the House of Commons of the Parliament of Great Britain from 1708 to 1800 and of the House of Commons of the Parliament of the United Kingdom from 1801 until 1868, when it was divided into North Ayrshire and South Ayrshire.

It elected one Member of Parliament (MP), using the first-past-the-post voting system.

The British parliamentary constituency was created in 1708 following the Acts of Union 1707 and replaced the former Parliament of Scotland shire constituency of Ayrshire.

The Ayrshire constituency represented the county of Ayrshire, minus the parliamentary burghs of Ayr and Irvine, which were components of the Ayr Burghs constituency.

The constituency elected one Member of Parliament (MP) by the first past the post system until it was divided into North Ayrshire and South Ayrshire for the 1868 general election.^{[1] [2] [3] [4] [5]}