​TROON, a police burgh, seaport and watering-place of Ayrshire, Scotland. Pop. (1901), 4764. It is situated 6 m. N. by W. of Ayr, and 35 m. S.W. of Glasgow by the Glasgow & South-Western railway. It has the best natural harbour in the county, with over a mile of quay e, a breakwater 5000 ft. long, and two graving docks. Shipbuilding is the leading industry, and there is a rope and sail factory. The town contains a public hall and library and reading-room. The municipality controls the Waterworks and gasworks. Fullarton House, 1 m. south-east, is a seat of the duke of Portland; and at Auchans, about 3 m. west, Susannah, Countess of Eglinton, in 1773 entertained Dr Johnson. Adjoining this estate stands the ruined castle of the Dundonalds.