Henrietta Ponsonby, Countess of Bessborough, born Lady Henrietta Frances Spencer, was the wife of Frederick Ponsonby, 3rd Earl of Bessborough; the couple were the parents of Lady Caroline Lamb. Her father, John Spencer, 1st Earl Spencer, was a great-grandson of John Churchill, 1st Duke of Marlborough. Her sister was Georgiana Cavendish, Duchess of Devonshire.