Ordgar (died 971) was Ealdorman of Devon in England. He was a great West Country landowner and apparently a close advisor[1] of his son-in-law Edgar the Peaceful, king of England. His daughter Ælfthryth was King Edgar's third wife and was the mother of King Æthelred the Unready (c.968 – 1016). He was created an ealdorman by King Edgar in 964.