Aleksandr Ivanovich Vvedenskii (Russian: Александр Иванович Введенский) (Vitebsk30 August 1889 — MoscowJuly 26, 1946) was a Russian spiritual.

He studied theology at the University of St. Petersburg and was dedicated to Russian-orthodox priest. After the Russian Revolution the Soviet of Vvedensky was in Petrograd (Saint Petersburg) chosen and he joined the revolutionaries. After the victory of the Bolsheviks in the Russian civil war, Alexander Vvedensky was leader of the so-called "living Church", a pro-Communist Group of priests who pursued close cooperation with the Bolsheviks and had separated from the Russian Orthodox Church. Furthermore, the attitude of the Bolsheviks towards the living Church not positive, because they prefer not to support received from the faithful.

Vvedensky claimed strong opposition against patriarch Tikhon by the Russian Orthodox Church. In October 1922 he was the nominal leader of Congregation of the old Apostolic Church, a collaboration of separate denominations after the revolution. In 1923 he became, although married, devoted to Bishop .

From 1922, Vvedensky was essentially the head of the living Church. During this time he took various titles, including: Metropolitan-Apologist-evangelist-Deputy First Hierarch. On 10 October 1941, he was appointed the "first Hierarch of the Russian Orthodox Church in the Soviet Union" with the title of the "most holy and blessed Lord and father" (Russian: Великий Господин и Отец "Святейший и Блаженнейший") and was essentially the head of the living Church. He tried to call himself patriarch, but which was never accepted by the majority of the Church and of december 1941 he returned to his less elegant title of the Roman Catholic Church.

His influence became less and less to the years passed. He reconciled after the raising of the living Church, not with the Russian Orthodox Church, which wanted to record him only as appeared again. He was not agree and died of heart failure as excommunicated.