He was born in Gamston, Nottinghamshire, the eldest son of Rev. Charles Fynes, prebendary of Westminster and perpetual curate of St. Margaret's, Westminster. For some generations his family bore the name of Fynes, but his father resumed the older family name of Clinton in 1821. His brother was the barrister and MP Clinton James Fynes Clinton.
He died at Welwyn, Herts, where he had purchased the residence and estate of the poet Edward Young. He had married twice; firstly Harriott, the daughter of Rev. Charles Wylde of Nottingham and secondly Katherine, the daughter of Rt. Rev. Henry William Majendie, Bishop of Bangor. They had 2 sons who predeceased their father and 9 daughters.
His reading was methodical (see his Literary Remains). His Fasti, on classical chronology, has required correction on the basis of later research.
His major works are:
- Fasti Hellenici, the Civil and Literary Chronology of Greece from the 55th to the 124th Olympiad (1824–1851), including dissertations on points of Greek history and Scriptural chronology; and
- Fasti Romani, the Civil and Literary Chronology of Rome and Constantinople from the Death of Augustus to the Death of Heraclius (1845–1850).
In 1851 and 1853 respectively he published epitomes of the above. The Literary Remains of H. F. Clinton (the first part of which contains an autobiography written in 1818) were edited by Clinton James Fynes Clinton in 1854.
- "FYNES (afterwards FYNES CLINTON), Henry (1781-1852), of Welwyn House, Herts. and Dean's Yard, Westminster, Mdx". History of Parliament Online. Retrieved 12 May 2017.