BEITH, a town and parish of Scotland, in the county of Ayr, and partly also in Renfrewshire. The town is in Ayrshire, on the Renfrew and Ayr Railway, and nine miles S.W. of Paisley. It carries on to a considerable extent the manufacture of bleached and coloured thread, and has several cotton manufactories. Pop. of the town in 1851, 2016.