Converts to Catholicism from Eastern Orthodoxy

Patriarch Yousef Yuhanna Meletios Macarios III Zaim (died 1672) was Orthodox Patriarch of Antioch from 1647 to 1672.

Adam Ipatii Potii (Ukrainian: Іпатій Потій, Polish: Hipacy Pociej, Belarusian: Іпацій Пацей) (1541—1613) was the Ukrainian Metropolitan of Kiev and Galychyna from 1599 to his death in 1613.

Patriarch Gregory III, surnamed Mammis or Μammas, was Ecumenical Patriarch during the period 1443–1450.

Isidore of Kiev, also known as Isidore of Thessalonica (Greek: Ἰσίδωρος τοῦ Κιέβου; Russian: Исидор; Ukrainian: Ісидор; b. Peloponnesus, 1385-d.Rome, 27 April 1463) was a Greek Metropolitan of Kiev, cardinal, humanist, and theologian.

Blessed Leonid Ivanovich Feodorov (Russian: Леонид Иванович Фёдоров; 1879–1935) was Exarch of the Russian Catholic Church, in addition to being a survivor of the GULAG.

Michael Rohoza (Polish: Michał Rahoza, Russian: Михаил Рагоза, Belarusian: Міхал Рагоза, Ukrainian: Михайло Рогоза) (died 1599) was the Ruthenian Metropolitan of Kiev, Galicia and All-Rus' from 1588 to his death in 1599.

Anton Atanas Sielava (Belarusian: Антон Сялява, Ukrainian: Антін Селява, Polish: Antoni Sielawa) (1583—1655) was the Metropolitan of Kiev, Galicia and Russia of the Ukrainian Greek Catholic Church from 1641 to his death in 1655.

John XI Bekkos (also, commonly, Beccus; name sometimes also spelled Veccus, Vekkos, or Beccos) (c. 1225 – March 1297) was Patriarch of Constantinople from June 2, 1275 to December 26, 1282, and the chief Greek advocate, in Byzantine times, of the reunion of the Eastern Orthodox and Roman Catholic Churches.

Josaphat Kuntsevych, O.

Meletius Smotrytsky (Ukrainian: Мелетій Смотрицький, Meletiy Smotryts’kyy; Belarusian: Мялецій Сматрыцкі; Polish: Melecjusz Smotrycki), né Maksym Herasymovytch Smotrytsky (c. 1577 – December 17 (27), 1633), Archbishop of Polotsk (Metropolitan of Kiev), was a writer, a religious and pedagogical activist of the Polish–Lithuanian Commonwealth, a Ruthenian linguist whose works influenced the development of the Eastern Slavic languages.

Joseph II (1360–1439) was Patriarch of Constantinople from 1416 to 1439.

George Akropolites, Latinized as Acropolites or Acropolita (Greek: Γεῶργιος Ἀκροπολίτης, Georgios Akropolitês, 1217 or 1220 – 1282), was a Byzantine Greek historian and statesman born at Constantinople.

Teophilus Seremi (also spelled Szeremi; died July 1697) was an Orthodox bishop and metropolitan of Bălgrad (of Transylvania) between 1692 and 1697.

Petro Parfenii was an Orthodox Bishop who united the Ruthenian Church with Rome.

Sister Eugenia Logvinovna Lashnyukova (1891, Mogilev, Russian Empire – ?) was an Orthodox (later the Greek-Catholic ) nun.

Father Eugene Ionnikievich Rozhitsky (Polish: Eugeniusz Różycki, born on 24 December 1896, Litvinkov, Russian Empire - ?) was an Orthodox (later the Greek-Catholic) priest.

Neophytos Nasri (1670–1731) was bishop of Saidnaya of the Melkite Greek Catholic Church and took a preeminent part in the 1724 split of the Melkite Church.

Mardarije Kornečanin (Serbian Cyrillic: Мардарије Корнећанин; fl. 1625–59) was the Serbian Orthodox Metropolitan (vladika) of Cetinje from 1637 to 1659, who after 1640 entered union with the Papacy.

Patriarch Cyril VI Tanas, also known as Cyril VI of Antioch (born in 1680, Damascus – died on January 10, 1760), became the first Patriarch of Antioch and All the East, and Alexandria and Jerusalem of the Melkite Greek Catholic Church following the schism of the Greek Orthodox Patriarchate of Antioch in 1724.

Atanasie Anghel Popa, (? - † 19 August 1713, Alba Iulia) was a Romanian Greek-Catholic bishop of Alba Iulia between 1698 and 1713.

Father Dmitry Arkadjevich Bagin (German: Martirij Bagin) (born 1956) is a Russian-Greek Catholic priest.

Euthymius Fadel of Ma’loula (died 1776) was bishop of Zahle and Forzol of the Melkite Greek Catholic Church and took a preeminent part in the 1724 split of the Melkite Church.

Patriarch Abdel-Karim Meletios Euthymius II Karmah (1572–1635) was Melkite Patriarch of Antioch from 1634 to 1635.

Valentin Arnoldevitch Tomberg (February 27, 1900 – February 24, 1973) was an Estonian-Russian Christian mystic, polyglot scholar and hermetic magician.

Sergey Vladimirovich Golovanov (Russian: Сергей Владимирович Голованов; born 25 July 1968 in Saransk, Republic of Mordovia) is a Russian Catholic priest of the Byzantine Rite.

Euthymios Michael Saifi (or Aftimios Sayfi, 1643–1723) was the Melkite Catholic bishop of Tyre and Sidon during the early 18th century.

Peter Vitchev, also known as Blessed Kamen Vitchev, was a Bulgarian Eastern Catholic and an Assumptionist priest who was martyred by the Bulgarian communist regime.

Simeon Vratanja (fl. ca. 1600–d. 1630) was the first bishop of the Eparchy of Vretanija (1609–11), the westernmost eparchy of the Serbian Patriarchate of Peć, and the first bishop of the Eastern Catholic Bishopric of Marča (1611–28).

Patriarch Constantine Cyril V Zaim (about 1655–1720), sometimes known also as Cyril III, was Greek Patriarch of Antioch.

Father Sergei Spytetsky (Polish: Sergiusz Spytecki) (12 July 1877- 28 August 1963) was an Orthodox (and later Greek-Catholic) priest.

Yuri Nikolayevich Jobbers (born on 13 August 1892 - died on 3 April 1969) was a Russian teacher and a Catholic convert from Russian Orthodoxy.

Hélène Iswolsky (Елена Александровна Извольская, born in 1896 - died in 1975, Cold Spring Harbor, New York, United States) was a Russian noblewoman, anti-communist political refugee, writer, translator and journalist.

Lazar Mladenov (Bulgarian: Лазар Димитров Младенов) (July 11, 1854 – March 4, 1918) was a Bulgarian Orthodox priest and, later, a member of the Bulgarian Uniat Church in the Ottoman Empire and a convert to Eastern Catholicism.

Arsenius Apostolius (Greek: Ἀρσένιος Ἀποστόλιος or Ἀρσένιος Ἀποστόλης; c. 1468 – 1538) was a Greek scholar who lived for a long time in Venice.