Otto (or Eudes) of Vermandois (29 August 979 – 25 May 1045), Count of Vermandois, was the son of Herbert III, Count of Vermandois and Ermengarde of Bar-sur-Seine. He succeeded his father Herbert III in 1015 as count of Vermandois. Otto donated property to Notre-Dame de Homblières by charter.
He married Pavia (or Patia) (b. 990). Their children were: