Odo II (French: Eudes le Champenois) (983 – 15 November 1037), Count of Blois, Chartres, Châteaudun, Provins, Rheims, and Tours from 1004 and Count of Troyes (as Odo IV) and Meaux (as Odo I) from 1022, was the son of Odo I of Blois and Bertha, daughter of Conrad of Burgundy. His career was spent in endless feudal warfare with his neighbours and suzerains, whose territories he tried to annex, and in a quest for a crown in Italy and Burgundy. He was uncharacteristically warlike even for his era and he solidified a large principality on the Loire in central France by his aggressive policies.
His first wife was Matilda, a daughter of Richard I of Normandy. After her death in 1006, Odo started a quarrel with his brother-in-law, Richard II of Normandy, over the dowry: part of the town Dreux. King Robert II, who had married Odo's mother, imposed his arbitration on the contestants in 1007, leaving Odo in possession of Dreux.
He tried to overrun the Touraine, but was defeated at the Battle of Pontlevoy by Fulk III of Anjou and Herbert I of Maine on 6 July 1016. War continued with Anjou and Odo attempted to take Saumur in 1025 but failed.
In 1023, he seized control of Troyes after the death of his cousin Stephen I without heirs. From there he attacked Ebles, the archbishop of Reims, and Theodoric I, the duke of Lorraine. Only an alliance between the king and the Emperor Henry II could stop Odo. He was forced to relinquish the county of Rheims to the archbishop.
He was offered the crown of Italy by the Lombard barons, but the offer was quickly retracted in order not to upset relations with the king of France. In 1032, he invaded the Kingdom of Burgundy on the death of Rudolph III. He retreated in the face of a coalition of the Emperor Conrad II and the new king of France, Henry I.
He died in combat near Bar-le-Duc during another attack on Lorraine. By his second wife, Ermengarde, daughter of Robert I of Auvergne, he had four children:
| Preceded by Theobald II |
Count of Blois 1004–1037 |
Succeeded by Theobald III |