Ayrshire, a county in the S. W. of Scotland, bounded W. by the frith of Clyde, and landward by the counties of Renfrew, Lanark, Dumfries, Kirkcudbright, and Wigtown; area, 1,149 sq. m.; pop. in 1871, 200,745. It is hilly on the southern and eastern sides, the principal hills rising to nearly 2,000 feet. It is intersected by several small rivers. About 10 m. off the coast lies the craig of Ailsa, the top of a submarine mountain with basaltic columns similar to those of Staffa. The county abounds in coal, particularly that known as blende coal, which is found in a state of coke; iron, lead, antimony, and various kinds of building stone are also found; and there is a granite valued for mill stones, and a black stone used in building ovens. The county is remarkable for its fine crops and for the general prosperity of its farmers. The manufactures are considerable in linens, woollens, cottons, leather, and other articles. The relics of antiquity, Druidical and Roman, are numerous, while there are also many ruins of buildings of the middle ages.

One of the most notable of these in point of interest is Turnberry castle, the ancestral residence of the Bruce. Capital, Ayr.