Russian diplomat and statesman who acquired political power for himself and his family during the reign of Tsar Peter II (reigned 1727–30).

Dolgoruky began his diplomatic career as an aide to his uncle Yakov Fyodorovich in Paris (1687). In 1700 he accompanied another uncle, Grigory Fyodorovich, to Poland and in 1706 replaced him as Russian ambassador there. He subsequently served as Russia's ambassador to Denmark (1707–20), France (1721–22), and Sweden (1725–27).

He shortly secured a position on the powerful Supreme Privy Council and arranged the betrothal of the young tsar to his niece, Yekaterina Alekseyevna. Peter II died suddenly (1730) before the marriage could take place, and Dolgoruky's involvement in intrigues concerning the succession—including the manufacture of a letter purporting to be the tsar's last will in which he appointed Yekaterina his successor—resulted in his banishment (1730), first to Siberia and then to the Solovetsky monastery. In 1739 he and two other Dolgorukys were found guilty of the forgery and beheaded.