Beatrix Beauclerk, Marchioness of Waterford

Beatrix Beauclerk, Duchess of St Albans, Marchioness of Waterford, GBE, DGStJ (25 March 1877 – 5 August 1953), born Beatrix Frances Petty-FitzMaurice, was a daughter of the 5th Marquess of Lansdowne and his wife, Maud.

On 16 October 1897, she married Henry Beresford, 6th Marquess of Waterford (and would be styled as Marchioness of Waterford); the couple had six children. The Marquess died in 1911, and on 19 August 1918, she remarried, to Osborne Beauclerk, 12th Duke of St Albans.