Patriarch Athenagoras I (born Aristokles Spyrou) (March 25, 1886 - July 6/7, 1972) was the Patriarch of Constantinople from 1948 to 1972.

His meeting with Pope John XXIII and Paul VI (1964) in the Second Vatican Council led to rescinding the 1054 excommunications of the Great Schism. This was a significant step towards restoring full communion between Rome and Constantinople, and it produced the Catholic-Orthodox Joint declaration of 1965.

He was born in 1886 in Tsaraplana , Epirus, Greece, and died in Istanbul, Turkey in 1972.

See also: Eastern Orthodoxy - Michael Cerularius