The given name Ivon finds its origins in the Breton language, spoken in the region of Brittany in northwestern France. Breton is a Celtic language closely related to Cornish and Welsh. Ivon is believed to be derived from the Breton word "evan," which means "young warrior" or "young fighter."

During the Middle Ages, the name Ivon was particularly popular among the Breton nobility and was associated with bravery and valor. One of the earliest recorded instances of the name can be found in the Breton epic poem "Bezen Buhez Mab Den" (The Life of a Human Being), written in the 14th century, where one of the main characters is named Ivon.

In the 12th century, a Breton knight named Ivon de Galles (Ivon of Wales) gained recognition for his exploits during the Crusades. He is mentioned in several chronicles of the time, including the "Gesta Regis Henrici Secundi" (Deeds of King Henry II) by the English historian William of Newburgh.

Another notable figure bearing the name Ivon was Ivon the Terrible, a Breton warlord who lived in the 11th century. He is described in the "Cartulaire de l'Abbaye de Redon" (Cartulary of the Abbey of Redon) as a fearsome warrior who terrorized the region of Brittany with his raids and battles.

In the 13th century, a Breton monk named Ivon Cassi (Ivon the Philosopher) wrote several treatises on theology and philosophy, which were widely studied in medieval universities across Europe.

Ivon de Viau, born in 1570, was a French poet and dramatist who gained fame for his tragedies and comedies inspired by ancient Greek and Roman works. His plays were performed at the court of King Henry IV and were celebrated for their wit and eloquence.

While the name Ivon has its roots in the Breton language and culture, it has also been adopted and used in other parts of Europe and beyond, particularly in areas with Celtic influence or connections to Brittany.