Adalberon, or Ascelin (died 19 July 1030/1031), was a French bishop and poet. He was a son of Reginar of Bastogne, the son of Gozlin, Count of Bidgau and Methingau, the son of Count Palatine Wigeric of Lotharingia.
Adalberon's uncle is Adalberon, Archbishop of Reims.
He studied at Reims He became bishop of Laon in 977.
The chronicler Richer of Rheims reports an accusation of 977 against him of adultery, with Queen Emma of Italy. Emma's son Louis V of France removed him from Laon in 981.
When Laon was taken by Charles, Duke of Lower Lorraine, in 988, Adalberon was put into prison, whence he escaped and sought the protection of Hugh Capet, king of France. Winning the confidence of Charles of Lorraine and of Arnulf, archbishop of Reims, he was restored to his see; but in 991 he gave Laon, together with Charles and Arnulf, into the hands of Hugh Capet.
Subsequently, he took an active part in ecclesiastical affairs, and died on July 19, 1030/1031. He showed his dislike of Odilo, Abbot of Cluny, and his followers, and his objection to persons of humble birth being made bishops.