Countess Elizaveta Romanovna Vorontsova (Russian: Елизавета Романовна Воронцова; 13 August 1739 – 2 February 1792) was a Russian noblewoman and lady-in-waiting. She was a mistress of Emperor Peter III of Russia (reigned February to July 1762). During their affair, rumors suggested that Peter had intentions of divorcing his wife Catherine (the future empress) in order to marry Vorontsova.[3]