Patriarch Teoctist was born on February 7, 1915, in the village Tocileni, Botosani county, in northeastern Romania. In 1929, he joined the Vorona Monastery. Later, he embraced monasticism, taking the name Teoctist, at the Bistrita Monastery.
He studied at the Orthodox Seminary in Cernica from 1932 until 1940 and graduated from the Orthodox Theological Faculty of Bucharest University in 1944.
On March 25, 1945, he was ordained to the priesthood in Iasi, where after his consecration to the episcpacy he served as vicar bishop from 1949 to 1962. From 1962 to 1973, he served as Bishop of Arad. From 1973 until 1977, he served as Archbishop of Craiova and Metropolitan of Oltenia. He served as Archbishop of Iasi and Metropolitan of Moldova and Suceava from 1977 until his election as Archbishop of Bucharest and Patriarch of Romania on November 9, 1986.