Sir John Fray (died 1461) was an English lawyer who was Chief Baron of the Exchequer and a Member of Parliament.
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.
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.