Lady Anne Churchill (27 February 1683 – 15 April 1716) was the second daughter of John Churchill, 1st Duke of Marlborough and Sarah Churchill, Duchess of Marlborough. As her father was created a sovereign prince by the Holy Roman Emperor Joseph I, Anne was also a princess of the Holy Roman Empire and later of Mindelheim.
Amongst her descendants are Sir Winston Churchill (from her son Charles), and Diana, Princess of Wales (from her son John).
She married 2 January 1700, Charles Spencer, 3rd Earl of Sunderland and had five children:
Her married name became Lady Spencer.
She held the office of Lady of the Bedchamber to Queen Anne from 1702 to 1712.
As a result of her marriage, Lady Anne Churchill was styled as Countess of Sunderland on September 28, 1702, but is not to be confused with her mother-in-law Anne Digby, also named Anne Spencer, Countess of Sunderland.
The title of Duke of Marlborough passed over from her elder sister Henrietta to her son Charles.
She died at the age of 33, and was buried on April 24, 1716 in Brington, Northamptonshire.
Anne, despite being a princess as a daughter of a sovereign prince, could not pass her Imperial titles to her children as the Empire operated Salic Law which prevented female succession.