Odo was the eldest son of Robert the Strong, Duke of the Franks, Margrave of Neustria, and Count of Anjou and Adelaide of Tours.

Guy is named as one of the couple's children in an Alan I's charter dated 28 August 903, but genealogist Christian Settipani has argued that the document is false.

For his skill and bravery in resisting the attacks of Vikings during the 885–886 Siege of Paris, Odo was chosen by the western Frankish nobles to be their king following the overthrow of Emperor Charles the Fat.

[10] Odo continued to battle against the Vikings and defeated them at Montfaucon, but was soon involved in a struggle with powerful Frankish nobles who supported the claim of Charles the Simple to the throne.

[13][14] Despite this, in 894 Arnulf declared his support for Charles the Simple, and after a conflict which lasted three years, Odo was compelled to come to terms with his rival and surrender a district north of the Seine to him.