John Horne Tooke (25 June 1736 – 18 March 1812), known as John Horne until 1782 when he added the name of his friend William Tooke to his own making his surname "Horne Tooke", was an English clergyman, politician, and philologist.
He was born in Newport Street, Long Acre, Westminster, the third son of John Horne, a poulterer in Newport Market. As a youth at Eton College, he described his father to friends as a "turkey merchant". Before Eton, he had been at school in Soho Square, in a Kentish village, and from 1744 to 1746 at Westminster School. He was left blind in his right eye after being injured in a schoolboy fight.
On 12 January 1754 he was admitted as sizar at St John's College, Cambridge, and took his degree of B.A. in 1758, as last but one of the senior optimes, Richard Beadon, his lifelong friend, afterwards Bishop of Bath and Wells, being a wrangler in the same year. Horne had been admitted on 9 November 1756, as student at the Inner Temple, becoming friends with John Dunning and Lloyd Kenyon. His father wished him to take orders in the Church of England, and he was ordained deacon on 23 September 1759 and priest on 23 November 1760.
For a few months he was usher (i.e., an assistant teacher) at a boarding school at Blackheath. On 26 September 1760 he became perpetual curate of New Brentford, the incumbency of which his father had purchased for him. Horne Tooke retained this poor living until 1773. During part of this time (1763–1764) he traveled on a tour in France, acting as a "bear-leader" (i.e., a travelling tutor) to a wealthy man.