Mečislovas Reinys (5 February 1884 – 8 November 1953) was a Lithuanian Roman Catholic titular archbishop and professor at Vytautas Magnus University.

During his short tenure, Reinys began negotiations regarding the Soviet–Lithuanian Non-Aggression Pact (signed in September 1926) and normalized Lithuania's relations with the Holy See that soured after the Concordat of 1925 with Poland.

On 4 April 1926, Pope Pius XI issued a bull which established the ecclesiastical province in Lithuania, including the Diocese of Vilkaviškis of which Reinys was named coadjutor bishop.

After a conflict with bishop Antanas Karosas, Reinys became more involved in diocesan affairs and started teaching at the Vilkaviškis Priest Seminary [lt] in 1934.

Mečislovas Reinys was born on 5 February 1884 on a farm in Madagaskaras [lt] near Daugailiai and Antalieptė, then part of the Russian Empire.

[1] His professors included Kazimieras Jaunius, Vincent Hadleŭski, Zygmunt Łoziński, Jurgis Matulaitis-Matulevičius, Adomas Jakštas [lt], Pranciškus Būčys, Jonas Mačiulis-Maironis, Jan Cieplak.

[15] As Soviets were about to be pushed out of Vilnius by the Polish forces in April 1919, they took several prominent Lithuanians as hostages, including Reinys, Felicija Bortkevičienė, Juozas Vailokaitis, and Liudas Gira,[1] and transported them to prisons in Daugavpils and Smolensk.

[5] On 24 July 1919, Vaclovas Sidzikauskas arranged a prisoner exchange in Daugailiai: 15 prominent Lithuanians, including Reinys, for 35 communists.

[18] In 1931, the ruling Lithuanian Nationalist Union reduced the Faculty of Theology, eliminated the department of psychology, and laid off 18 professors.

[27] With the help of Archbishop Jurgis Matulaitis-Matulevičius, Reinys reestablished diplomatic contacts with the Holy See and agreed to a three-step plan to normalize the relations.

[30] The Lithuanian government prepared a protest note which Reinys personally delivered to Ishii Kikujirō, president of the Council of the League of Nations, on 12 March 1926.

[31] The negotiations began in December 1925 when People's Commissar of Foreign Affairs Georgy Chicherin stopped in Kaunas on his way to Moscow.

[40] He also conducted canonical visitations of various parishes,[41] led three-day Spiritual Exercises,[42] inspected religious education in schools,[43] etc.

[34] Commemorating the 550th anniversary of the Christianization of Lithuania, he visited 52 parishes, delivered 67 sermons and 46 speeches, participated in congresses and other events of Lithuanian organizations.

[34] Reinys was also granted the rights of an apostolic administrator in the event of a vacancy on the episcopal see in Vilnius, with the authority of a residential bishop.

[55] On 22 March, Germans arrested archbishop Jałbrzykowski and archdiocese's chancellor Adam Sawicki [pl] and interned them in Marijampolė.

[59] The documents only mention that in 1943, he unsuccessfully attempted to secure the release of two priests, Józef Grasewicz and Władysław Małachowski, who were connected with the cult of the Divine Mercy.

[59] During an air raid by the Soviet forces on the night of 23 March 1942, a bomb fell onto the clergy house of the Church of Saint Nicholas, Vilnius.

[60] On 17 June 1942, Reinys called for the organization of two days of solemn services in gratitude for the fact that "German and allied forces had removed Bolshevik atheism from our region," as well as masses for the victims of the war.

After complaints reached the Vatican, Reinys defended that the reinstatement of either the litany or the feast were not possible due to the political situation and offered to resign.

[68] The Vatican prohibited Reinys from changing of the language of sermons, as they were the exclusive responsibility of the Polish Episcopal Conference, and the actual ordinary of the diocese was in exile.

Surviving documents show that NKVD collected reports from 12 different agents in 1940–1941 that focused on Reinys' sermons and personal attitudes towards the Soviet regime and relations between Polish and Lithuanian clergy.

[89] It listed specific instances of Reinys' anti-Soviet activities, which included participating in the activities of the Catholic Action Center in interwar Lithuania, publishing various anti-Soviet articles during the German occupation, providing financial support (300 Reichsmarks for the purpose of purchasing books)[90] to a battalion of the Lithuanian Auxiliary Police, attending a meeting of Lithuanian bishop in September 1944 which decided to seek religious lessons in schools and military chaplains in Red Army units, persuading bishop Vincentas Borisevičius not to cooperate with the NKGB in December 1945, and delivering a sermon defending the Vatican after a critical article was published in Sovetskaya Litva in June 1947.

[98] His cellmates included Russian monarchist Vasily Shulgin and leader of Latvian Jews Mordehai Dubin, as well as German diplomat Gotthold Starke [de] and British soldier Frank Kelly who later wrote memoirs about Reinys in prison.

[102] Starting in 1907, he published various articles in Lithuanian periodicals, including Šaltinis, Draugija, Viltis, Tėvynės sargas, Pavasaris, Ateitis, XX amžius.

[102] Researcher Aldona Vasiliauskienė has attributed about 50 articles published in Vilniaus garsas [lt] in 1920–1922 that were signed under the pen name Dr. Mututa to Reinys.

[106] In 1921, Reinys translated and published a 242-page psychology textbook by Georgy Chelpanov which was used by various schools during the entire interwar period.

[105] In this work, Reinys surveys developments in scientific racism, particularly the use of anthropology and craniometry to distinguish "higher" and "lower" races.

He criticized works of Arthur de Gobineau, Houston Stewart Chamberlain, Alfred Rosenberg based on biology, religion, philosophy, pedagogy, and argued that there is no such thing as the Aryan race.

[17] This caused several diplomatic incidents when Reinys was the Minister of Foreign Affairs and dignitaries noticed that they were toasted not with a glass of wine, but rose colored water.