Newmilns is a village in the burgh of Newmilns and Greenholm, in East Ayrshire, Scotland. It has a population of 3,057 people and lies on th…Newmilns is a village in the burgh of Newmilns and Greenholm, in East Ayrshire, Scotland. It has a population of 3,057 people and lies on the A71, around seven miles east of Kilmarnock and twenty-five miles southwest of Glasgow. It is situated in a valley through which the River Irvine runs and, with the neighbouring towns of Darvel and Galston, forms an area known as the Upper Irvine Valley.