Major-General Henry Gladwin (1729 or 1730 – 22 June 1791) was a British army officer in colonial America and the British commander at the Siege of Fort Detroit during Pontiac's Rebellion in 1763. He served in the disastrous campaign of Edward Braddock and in other actions in the French and Indian War but is best remembered for his defense of Detroit in Pontiac's Rebellion.
Henry was born in 1729 or 1730 at Stubbing Court, near Wingerworth, Chesterfield, in Derbyshire. He was the eldest son of Henry Gladwin (1692–1763) by his second wife Mary daughter of John Digby Dakeyne of Stubbing Edge Hall. They were married on 28 Oct 1728 in Wingerworth. His father's first wife Marina Holland, heiress of Stubbing Court died in childbirth May 1727 Mary Dakeyne was the sister and heiress of John Dakeyne. He was a great-grandson of Thomas II Gladwin (1628/9-1697) of Tupton Hall, now Tupton Hall school, in the parish of Wingerworth near Chesterfield, Derbyshire, Sheriff of Derbyshire in 1668. Thomas II was the second son and principal heir of Thomas I Gladwin (c. 1598 – 1667) of Boythorpe and Tupton, Derbyshire, an eminent lead merchant who raised an estate of £800 or £900 per annum.
One of Gen. Henry's brothers was John Gladwin (1731–1822) of Mansfield, Nottinghamshire, a lawyer and steward of the royal Sherwood Forest and attorney and steward of the manor of Mansfield to William Cavendish-Bentinck, 3rd Duke of Portland (1738–1809), Prime Minister of Great Britain, of Welbeck Abbey, Nottinghamshire and Burlington House, London. John's 4th daughter Dorothy Gladwin (died 1838) "Lady Dolly" married in 1787 Francis Eyre (1762–1827)(later Radclyffe-Livingstone-Eyre), self styled 6th Earl of Newburgh, of Hassop Hall, Bakewell, Derbyshire. All her 10 children died without issue and the last two earls, both her sons, supposedly had settled their vast estates, producing £50,000 per annum, on their mother's family, the Gladwins. In 1885 the estate was claimed, apparently without success, by Mr Gladwin Cloves Cave of Rossbrin Manor, Cork, Ireland, a great-grandson of Mrs Elizabeth Cloves, "Lady Dolly's" eldest sister.