Count Matvey Alexandrovich Dmitriev-Mamonov (Russian: Матвей Александрович Дмитриев-Мамонов; 25 September [O.S. 14 September] 1790 in Moscow – 23 June [O.S. 12 June] 1863 at Vassilyevskoye manor, today within the city borders of Moscow) - was a Russian figure of public life and writer, organiser and chief of the Mamonov regiment during the Napoleonic wars, major general (1813), and founder of the pre-Decembrist Russian Order of Chivalry. He held a considerable estate, including the manor Dubrovitsy near Moscow. In 1825 he refused the oath to Tsar Nicholas I and was declared insane. For the rest of his life he stood under trusteeship at Vassilyevskoye manor, which became known as Mamonov's Dacha.