Henry FitzRoy, 1st Duke of Grafton, KG (28 September 1663 – 9 October 1690) was an illegitimate son of King Charles II of England and his mistress Barbara Villiers.

His mother was the daughter of William Villiers, 2nd Viscount Grandison, a colonel of one of King Charles I's regiments who was killed in action during the Civil War.

A wedding ceremony took place on 4 November 1679 witnessed and recorded by John Evelyn in his diary of that date describing him as "exceedingly handsome, by far surpassing any of the Kings other naturall Issue".

[2] In that year, he received a warrant to supersede Sir Robert Holmes as Governor of the Isle of Wight, when the latter was charged with making false musters.

[5] In October 1697, his widow, Isabella, married Sir Thomas Hanmer,[1] a young Flintshire baronet, who became Speaker of the House of Commons and an authority on the works of William Shakespeare.