Gavril Ilyich Myasnikov (Russian: Гаврии́л Ильи́ч Мяснико́в; February 25, 1889, Chistopol, Kazan Governorate – November 16, 1945, Moscow), also transliterated as Gavriil Il'ich Miasnikov, was a Russian communist, a metalworker from the Urals, who participated in the Revolution of 1905 and became a Bolshevik underground activist in 1906. Tsarist police arrested him and he spent over seven years at hard labor in Siberia. In 1917, Myasnikov was active in factory committees, the soviet, and the Bolshevik party in his hometown of Motovilikha and in Perm.
Gabriel Myasnikov is known as the execution initiator and killer of the Grand Duke Michael Alexandrovich of Russia (1918).
Myasnikov was a Left Communist in 1918, opposed to the Treaty of Brest-Litovsk. He was dissatisfied with elements of Party policy toward workers, but he did not support the Workers Opposition in 1920-21. Myasnikov disagreed with the Workers' Opposition's call for unions to manage the economy. Instead, in a 1921 manifesto, Myasnikov called for “producers’ soviets” to administer industry and for freedom of the press for all workers. Leaders of the Workers Opposition Alexander Shlyapnikov and Sergei Medvedev feared that Myasnikov's proposals would give too much power to peasants. Despite their disagreements, however, they supported Myasnikov's right to voice criticisms of Party policy. Along with former members of the Workers' Opposition, Myasnikov signed the "Letter of the Twenty-Two" to the Comintern in 1922, protesting the Russian Communist Party leaders' suppression of dissent among proletarian members of the Communist Party.