Otto (or Eudes) of Vermandois (29 August 979 – 25 May 1045), Count of Vermandois, was the son of Herbert III, Count of Vermandois and Hermengarde of Bar-sur-Seine. Otto donated property to Notre-Dame de Homblières by charter. He acceded to the county after the death of his older brother, Adalbert II, Count of Vermandois, in 1015.
He married Pavia (or Patia) (b. 990). Their children were:
Herbert IV, Count of Vermandois.
Bachrach, Bernard S.; Bachrach, David S. (2018). Deeds of the Bishops of Cambrai. Routledge.
Le Jan, Régine (2003). Famille et pouvoir dans le monde franc (VIIe-Xe siècle) (in French). Publications de la Sorbonne.