Nestorius (; in Greek: Νεστόριος; c. 386 – c. 451) was Archbishop of Constantinople from 10 April 428 to August 431 (when the emperor Theodosius II confirmed his condemnation by the Cyrillian faction at Ephesus on 22 June). His teachings included a rejection of the long-used title of Theotokos ("Mother of God") for the Virgin Mary, and were understood by many to imply that he did not believe that Christ was truly God. This brought him into conflict with other prominent churchmen of the time, most notably Cyril of Alexandria, who accused him of heresy. Nestorius sought to defend himself at the First Council of Ephesus in 431, but instead he found himself formally condemned for heresy by a majority of the bishops and subsequently removed from his see. On his own request he retired to his former monastery in or near Antioch. In 435 Theodosius II sent him into exile in Upper Egypt, where he lived on till 450 or 451, strenuously defending his orthodoxy. His last major defender within the Roman Empire, Theodoret of Cyrrhus, finally agreed to anathematize him in 451 (during the Council of Chalcedon); from then on he had no defenders within the empire. But the Church of the East (that is, the Church in eastern Mesopotamia and Persia, under Sassanian rule) never accepted his condemnation. This led later to western Christians giving the name the 'Nestorian Church' to the Church of the East (the modern Assyrian Church of the East), even though it never regarded him as an authoritative teacher. The discovery and publication of his 'Book [or Bazaar] of Heraclides at the beginning of the 20th century led to a reassessment of his theology in western scholarship. It is now generally agreed that his ideas were not far from those that eventually emerged as orthodox, but the orthodoxy of his formulation of the doctrine of Christ is still controversial. This is due to the fact that the Second Council of Constantinople of 553 a.D. confirmed the validity of the condemnation of Nestorius, refuting the impius letter of Iba that affirms that Nestorius was condemned without the due inquiry.

Nestorius (gr. Νεστόριος, * nach 381; † um 451 in Akhmim, Oberägypten) war 428 bis 431 Patriarch von Konstantinopel. Er wurde nach dem Konzil von Ephesus seines Amtes enthoben, weil er behauptete, dass Maria Christusgebärerin und nicht Gottesgebärerin war. Er starb in der Verbannung in Kasaviti auf der Insel Thasos.

Nestorius ou Nestorios (en grec Νεστόριος, né à Antioche vers 381 - mort en exil en Égypte en 451) fut patriarche de Constantinople du 10 avril 428 au 11 juillet 431. Ses prises de position sont à l'origine du nestorianisme.

Nestorius (grekiska Νεστόριος), född omkring 381, död omkring 451 i Akhmim, var patriark av Konstantinopel mellan 428 och 431. Han gav upphov till den, av romersk-katolska kyrkan kätterska, nestorianismen.

Nestoriusz (384-451) - mnich rodem z Syrii, teolog, świetny mówca i kaznodzieja. Jako patriarcha Konstantynopola (428-431) bezwzględnie zwalczał arian i macedonian. Opierając się na naukach Diodora z Tarsu i Teodora z Mopsuestii walczył przeciw herezji apolinaryzmu, głoszącej, że człowieczeństwo Jezusa nie było pełne, co doprowadziło go do przekonań dokładnie odwrotnych. Powstałą w ten sposób herezję, od imienia jej twórcy, nazwano nestorianizmem. Pełny jej wykład Nestoriusz dał w publicznym wystąpieniu na Boże Narodzenie 429 roku.