Odo of Cambrai (Odoardus, also Odo of Tournai) (Orléans 1060 – 1113) was a Benedictine monk, scholar and bishop. He was born at Orléans.
In 1087 he was invited by the canons of Tournai to teach in that city, and there soon won a great reputation. He became a Benedictine monk (1095) in St. Martin's Abbey, Tournai, of which be became abbot later. In 1105 he was chosen Bishop of Cambrai, and was consecrated during a synod at Reims. For some time after he was unable to obtain possession of his see owing to his refusal to receive investiture at the hands of Emperor Henry IV, but the latter's son Henry restored the See of Cambrai to Odo in 1106.
He laboured diligently for his diocese, but in 1110 he was exiled on the ground that he had never received the cross and ring from the emperor. Odo retired to Anchin Abbey, near Pecquencourt, where he died without regaining possession of his diocese. Many of his works are lost; those extant will be found in Migne.
His treatise De peccato originali in three books, composed between 1095 and 1105, discuss the problrm of universals, and of genera and species from a realist viewpoint.