Henrietta Waldegrave, Baroness Waldegrave

Henrietta Butler, Viscountess Galmoye (previously Henrietta Waldegrave, Baroness Waldegrave, née FitzJames) (1667 – 3 April 1730) was an illegitimate daughter of James Stuart, Duke of York, subsequently King of England, Scotland and Ireland, by his mistress, Arabella Churchill (a sister of the first Duke of Marlborough). During her first marriage, she became Lady Waldegrave, and she later became the titular Countess of Newcastle (in the Jacobite Peerage) upon her second marriage.

She was the older sister of the celebrated James FitzJames, Duke of Berwick. She was brought up a Roman Catholic and married into a family of the same religion. On 29 November 1683, she married Henry Waldegrave, 1st Baron Waldegrave, and by him had two children:

She accompanied her father and his queen in their exile and lived some years at St. Germains. After her husband's death in 1689, she was involved with an Irish soldier, Mark Talbot, before she married Piers Butler, 3rd Viscount Galmoye, on 3 April 1695. He had been created Earl of Newcastle in the Jacobite Peerage. The marriage was childless. She died in 1730 and was buried in .

She is an ancestor of the Earls Spencer of Althorp, Diana, Princess of Wales, and also Diana's sons, Prince William, Duke of Cambridge and Prince Harry.