Count Semyon Romanovich Vorontsov was a Russian diplomat from the aristocratic Russian Vorontsov family. He resided in Britain for the last 47 years of his life, from 1785 until his death in 1832, during which time he was the Russian ambassador to the Kingdom of Great Britain from 1785 to 1800 and to the United Kingdom from 1801 to 1806.

Countess Elizaveta Romanovna Vorontsova was a Russian noblewoman and lady-in-waiting. She was a mistress of Emperor Peter III of Russia. During their affair, rumors suggested that Peter had intentions of divorcing his wife Catherine in order to marry Vorontsova.