Paisius was a Serbian abbot martyred by the Ottoman authorities at Belgrade in 1814, during the period of upheaval that followed the collapse of the First Serbian Uprising. He is associated with the Moštanica Monastery, and according to the historical record served as hegumen of the Annunciation Monastery at Trnava, near Čačak; the monks of Trnava are reported to have included the Moštanica community, which had fled there after an earlier failed anti-Ottoman revolt. He is commemorated on December 17 together with the deacon Habakkuk (Avakum), with whom he suffered.
After the revolt led by Karađorđe had been suppressed in 1813, the clergy and monks of Trnava took part in a further uprising organized under Hadži-Prodan Gligorijević. The rising broke out on the Feast of the Exaltation of the Cross (September 14) but was quickly crushed by Ottoman forces. Among its organizers, the sources name the Trnava clergy: the hegumen Paisius, the hieromonk Genadije, the deacon Avakum, and the priest Radovan Vujović.
Paisius and the deacon Avakum were among the captives sent to Suleiman Pasha at Belgrade. The synaxarion relates that in their prison cell the deacon Avakum sang the Compline hymn 'God is with us' while Paisius prayed. The Ottoman authorities offered to release any prisoner who would convert to Islam; some accepted, but the greater number refused to deny Christ and were put to death. By tradition Paisius was made to carry to the place of execution the stake on which he was then impaled, and as he was raised upon it he cried out, 'Glory to God.'
Paisius attained martyrdom on December 17, 1814. He and Avakum were afterward numbered among the New Martyrs (novomučenici) of the Serbian Church. Their joint commemoration is kept on December 17 (December 30 on the New Style) and is especially venerated in the village of Trnava.