Antonievo-Siysky Monastery (Антониев-Сийский монастырь in Russian) is a Russian Orthodox monastery that was founded by Saint Anthony of Siya deep in the woods, 90 km to the south of Kholmogory, in 1520. Currently the monastery is located in Kholmogorsky District of Arkhangelsk Oblast in Russia, inside the nature protected area, Siysky Zakaznik.