Autchar (also Otachar or Otgar) was a Frankish nobleman. He served Pippin III as a diplomat in 753 and followed Carloman I after the division of the kingdom in 768. In 772, refusing to accept Carloman's brother Charlemagne as king, he went into exile in the Lombard kingdom with Carloman's widow and sons. He was captured when Charlemagne invaded the kingdom in 773. His role in the fall of the Lombard kingdom was the subject of legendary embellishment a century later and in the chansons de geste he evolved into the figure of Ogier the Dane.