Prince Ivan Sergeyevich Gagarin (???? ????????? ???????; born in Moscow, 1 August 1814; died in Paris, 19 July 1882) was a Russian Jesuit, known also as Jean-Xavier after his conversion from Orthodoxy to Roman Catholicism.
He was of the Gagarin family, which traces its origin to the medieval rulers of Starodub-on-the-Klyazma.