Sir John Fray (died 1461) was a lawyer who served as Lord Chief Baron of the Exchequer and had considerable experience of rivers and watermills.
Fray had the commission for maintaining the navigation of the River Lea around the years 1430–1440. He owned watermills in Essex and interests in other property across the country. These included Cowley Hall in Hillingdon which adjoined the Frays River. The Frays River is a branch of the River Colne which may have been developed to feed watermills in the area. It is said that John Fray arranged for the cutting of a link from the Colne to a tributary rising in Harefield to increase the water volume. .[1]
He was also second husband of Agnes Danvers, and the grandfather of Sir William Waldegrave.