St. Andronik Monastery, often transliterated as Andronikov Monastery (Russian: Андро́ников монасты́рь, Спа́со-Андро́ников монасты́рь, or Андро́ников Нерукотво́рного Спа́са монасты́рь) is a former monastery on the left bank of the Yauza River in Moscow, consecrated to the Holy Image of Saviour Not Made by Hands and containing the oldest extant cathedral in Moscow.
The monastery was established in 1357 by Metropolitan Alexis as a way of giving thanks for his survival in a storm. Its first hegumen was Saint Andronik, one of Sergii Radonezhsky's disciples. The extant four-pillared Saviour Cathedral was constructed from 1420–1427. The great medieval painter Andrei Rublev spent the last years of his life at the monastery and was buried there. In addition, one of the largest mass graves for lay brothers (called скудельница, skudelnitsa) was located on the cloister's premises.
In the second half of the 14th century, a monastic quarter formed outside the walls of the Andronikov Monastery, which started producing bricks for the ongoing construction of the Moscow Kremlin (1475). From its beginning, Andronikov Monastery was one of the centres of book copying in Muscovy. Manuscript collection of the cloister included most of the works by Maximus the Greek. In August 1653, archpriest Avvakum was held under arrest at this monastery.
Andronikov Monastery has been ransacked on numerous occasions (1571, 1611, 1812). In 1748 and 1812, its archives were lost in fires. In the 19th century, there were a theological seminary and a library on the cloister's premises. By 1917, there had been seventeen monks and one novice in the monastery.The monastery cathedral from the 1420s is the oldest surviving building in Moscow.