Sir John Hely (born c. 1650 – died 7 April 1701) was an English-born judge in Ireland, who held office as Chief Baron of the Irish Exchequer, and who was the founder of the prominent landowning Hely family of Foulkscourt Castle, Johnstown, County Kilkenny. The family is chiefly remembered for developing the village of Johnstown.
He was born in London, the eldest son of James Hely. He entered Lincoln's Inn in 1670 and was called to the Bar in 1679.