Walter Montgomerie Neilson was an eminent Scottish locomotive and marine engineer and manufacturer. His father, James Beaumont Neilson, invented the hot blast furnace. He ran the family business, Neilson & Company (originally Neilson & Mitchell), from 1843, a ship engine and locomotive manufacturer based in Glasgow. Due to the expansion of the British empire, the locomotive industry flourished and Neilson locomotives were exported globally. After his retirement in the late 1870s, his business became Neilson, Reid & Co (with James Reid added as partner), and later merged with other locomotive manufactures to form the North British Locomotive Co. Ltd. He was at one point President of the Institution of Engineers and Shipbuilders in Scotland, as well as being a member of the Institution of Civil Engineers, the Institution of Mechanical Engineers, the Institution of Naval architects, the Society of Arts, and the United Service Institution, London. He was elected chairman of the Technical College of Glasgow in 1872.He was also was president of the Mechanics Institution from 1866 to 1874. He was a prominent figure in local politics, the military and Freemasonry, acting as the Freemasons Grandmaster of Glasgow. He died in Florence, Italy. where he had an estate.