ARDROSSAN, a seaport town of Ayrshire, Scotland, situated on the Firth of Clyde opposite the island of Arran, and 16 miles north-west of Ayr. The town has lately been much improved, and is a favourite resort of visitors during the bathing season. Large sums were expended by the late Earl of Eglinton in forming the harbour, which is sheltered by a pier and a small islet, and has a lighthouse with a fixed light on the north-east breakwater, in Lat. 55. 38. 27. N. Long. 4. 49. 28. W. It has a branch railway uniting it with the Glasgow and Ayr lines at Kilwinning, and communication by steamers with Arran, Belfast, and Liverpool. Pop. in 1851, 2071. See AYRSHIRE.