Isḥaq of Nineveh (Syriac: ܡܪܝ ܐܝܣܚܩ ܕܢܝܢܘܐ, romanized: mār isḥāq d-ninwē; Arabic: إسحاق النينوي Ishaq an-Naynuwī; c. 613 – c. 700), also remembered as Saint Isaac the Syrian (Ancient Greek: Ἰσαὰκ ὁ Σύρος), Isaac of Nineveh, Abba Isaac, Isaac Syrus and Isaac of Qatar, was a 7th-century Syriac Christian bishop of the Church of the East, and theologian best remembered for his written works on Christian asceticism. He is regarded as a saint in the Church of the East, Roman Catholic, and Eastern Orthodox churches. His feast day falls, together with 4th-century theologian and hymnographer St. Ephrem the Syrian, on January 28.
