Odo I (also spelled Eudes) (c. 950 – 12 March 996), Count of Blois, Chartres, Reims, Châteaudun and Omois, lord of Provins, was the son of Theobald I of Blois and Luitgard, daughter of Herbert II of Vermandois.

[1] He received the title of count palatine from King Lothair of West Francia.

In the 970s, in the wars for control of Brittany, he subjugated the county of Rennes and Count Conan I affirmed the rights of his family in the region.

[3] Hugh Capet, Bouchard of Vendome, Richard I of Normandy and Fulk Nerra, assembled against him and retook Melun in late 991.

In the winter of 995 – 996, they besieged Langeais, however Odo became ill and was taken to the monastery of Marmoutier at Tours where he died on 12 March 996.