Theodosius of Chernigov (secular name Theodosius Polonitsky-Uglitsky) was an Archbishop of Chernigov in the late seventeenth century, venerated as a wonderworker and glorified as a saint of the Russian Orthodox Church in 1896. Born in the 1630s in the Podolsk region to a priest named Niketas and his wife Maria, Theodosius received his formation at the Kiev Brotherhood school and took monastic vows at the Kiev Caves Lavra — the ancient center of Russian monasticism. He served successively as prior of several monasteries in Ukraine, demonstrating particular skill in restoring communities that had fallen into decline.
Theodosius was consecrated Archbishop of Chernigov on September 13, 1692, and in just over three years of episcopal ministry founded new monasteries, established a skete, and consecrated multiple churches before his death on February 5, 1696. He was buried in the Cathedral of Saints Boris and Gleb in Chernigov. His successor as Archbishop of Chernigov, Saint John (Maximovitch), was reportedly healed of a grave illness through Theodosius's intercession. The glorification of Theodosius — the formal recognition of his sainthood — took place on September 9, 1896, the date that became his secondary feast. His primary commemoration is on February 5, the anniversary of his repose.