Barbara Urszula Sanguszko, née Dunin (pseudonym: A Dame; A definite Polish dame; definitely a worthy dowager; 4 February 1718 – 2 October 1791 in Warsaw) was a Polish noblewoman, poet, translator, and moralist during the Enlightenment in Poland.
She organised and hosted a salon in Poddebice, where the gathering of intellectuals, artists and politicians was modelled after French 18th-century salons.
Sanguszko was known for her piety and philanthropy.
She was the third wife of the much older magnate and Grand Marshal of Lithuania, Duke Pawel Karol Sanguszko (1682–1750).