Louisa Grace Beauclerk, Duchess of St Albans (née Lady Louisa Grace Manners; 4 December 1777 – 19 February 1816), was a British noblewoman and the second wife of Aubrey Beauclerk, 6th Duke of St Albans.

She was one of the youngest of the seven children of John Manners, MP, and his wife Louisa Tollemache, 7th Countess of Dysart.

[2] Her nephew, Lionel Tollemache, 8th Earl of Dysart, succeeded her mother in the earldom when the latter died in 1840, aged 95.

The new duchess was said to have been "one of the brightest stars in the fashionable hemisphere" in the early years of her marriage.

Louisa had been "in a delicate state of health" since the death of her husband, and contemporary reports say that she died three hours after the child.