There are multiple origins and meanings for the name Ivo:
1. The name is derivative form of the given name Ives - "yew tree"
2. South and West Slavic form of the biblical name Iohannes meaning - "God is gracious".
Saint Ivo of Kermartin (17 October 1253 - 19 May 1303), also known Yvo or Iyes, as Erwann (in Breton) and as Yves Hélory (also Helori or Heloury in French), was a parish priest among the poor of Louannec, the only one of his station to be canonized in the Middle Ages. He is the patron of Brittany, lawyers, and abandoned children. His feast day is May 19. Poetically, he is referred to as "Advocate of the Poor."
Born at Kermartin, a manor near Tréguier in Brittany, Ivo was the son of Helori, lord of Kermartin, and Azo du Kenquis. In 1267 Ivo was sent to the University of Paris, where he graduated in civil law. He went to Orléans in 1277 to study Canon law. On his return to Brittany having received minor orders he was appointed "official", the title given to an ecclesiastical judge, of the archdeanery of Rennes (1280); meanwhile he studied Scripture, and there are strong reasons for believing that he joined the Franciscan Tertiaries sometime later at Guingamp. He was soon invited by the Bishop of Tréguier to become his official, and accepted the offer in 1284. He displayed great zeal and rectitude in the discharge of his duty and did not hesitate to resist the unjust taxation of the king, which he considered an encroachment on the rights of the Church; by his charity he gained the title of advocate and patron of the poor. Having been ordained he was appointed to the parish of Tredrez in 1285 and eight years later to Louannec, where he died of natural causes, after a life of hard work and repeated fasting.