Julian of Toledo (642–690) was born to Jewish parents in Toledo, Hispania, but raised Christian. He was well educated at the cathedral school, was a monk and later abbot at Agali, a spiritual student of Saint Eugene II, and archbishop of Toledo. He was the first bishop to have primacy over the entire Iberian Peninsula—a position he has been accused of securing by being complicit in 680 in the supposed poisoning of Wamba, king of the Visigoths —and he helped centralize the Iberian Church in Toledo. His elevation to the position of primate of the Visigothic church was a source of great unhappiness among the kingdom's clergy. And his views regarding the doctrine of the Trinity proved distressing to the Vatican.

He presided over several councils and synods and revised the Mozarabic liturgy. A voluminous writer, his works include Prognostics, a volume on death; a history of King Wamba's war with dux Paul in Septimania; and a book on the future life (687). Though by disposition a kind and gentle man, he encouraged the Visigothic kings in Hispania to deal harshly with the Jews. For example, in presiding over the Twelfth Council of Toledo, he induced King Erwig (whom, again, he has been accused of helping in the deposing of Wamba) to pass severe anti-Jewish laws. At Erwig's request, in 686, he wrote De Comprobatione Aetatis Sextae Contra Judaeos, a work dealing with messianic prophesies of the Bible in a way intended to convert the Jews.

He died at Toledo in 690 of natural causes. Julian's memorial is held March 8.