Countess Ekaterina Semyonovna Vorontsov (October 24, 1784 in Saint Petersburg – March 27, 1856 in London), sometimes spelled Woronzow, was the daughter of Semyon Vorontsov, the Russian ambassador in Britain from 1785, and the only sister of Prince Mikhail Vorontsov, Viceroy of New Russia and Caucasus (1782–1856). She was also a niece of Princess Dashkova, a friend of Catherine the Great and a conspirator in the coup d'état that deposed Czar Peter III and put his wife on the throne.
In 1808, she married George Herbert, 11th Earl of Pembroke as his second wife and became Countess of Pembroke, Lady Pembroke, the chatelaine of Wilton House, Wiltshire. The Wilton Estate, Salisbury held an exhibition on her life titled Through Russian Eyes in August 2008.