The Diocese of Russia and New Nakhichevan (Armenian: Հայաստանեայց Առաքելական Եկեղեցու Ռուսաստանի և Նոր Նախիջևանի Հայոց Թեմ; Russian: Российская и Ново-Нахичеванская епархия) is one of the historical dioceses of the Armenian Apostolic Church, whose jurisdiction includes most of Russia, as well as the territory of Belarus, Kazakhstan, Kyrgyzstan, Moldova, Tajikistan, Turkmenistan, and Uzbekistan.

Only in the 1950s did clergy begin to visit Armenian villages in the Rostov region, and in 1955 the church in Moscow was reopened.

But the churches in the USSR really began to strengthen in the late 1970s, when the political situation in the country changed and Tiran (Kyuregyan)[2] was appointed head of the diocese in 1976.

During Soviet times, the diocese included the entire territory of the USSR outside of Transcaucasia.

Under him, there is a Diocesan Council, which, in addition to Church figures, includes prominent Armenians of Russia.