Saint Ivo of Chartres (also Ives, Yves, or Yvo; Latin: Ivo Carnutensis; c.
1040 – 23 December 1115) was the Bishop of Chartres, France from 1090 until his death, and an important canonist during the Investiture Crisis.
Ivo is claimed to have studied at the Abbey of Bec in Normandy under Lanfranc of Canterbury, where he would have met St.
Anselm of Canterbury, the great scholastic theologian.
In 1067 or not much later, he became, at the desire of his bishop, prior of the canons of Saint-Quentin at Beauvais.
As Bishop of Chartres and a canonist he contended strongly against simony and opposed King Philip I of France's repudiation of his wife Bertha of Holland in order to marry Bertrade of Anjou in 1092.
Ivo was briefly imprisoned for this opposition.
Three extensive canonical works, namely Tripartita, Decretum, and Panormia, are attributed to him.