Mercadier (died 10 April 1200) was a famous Occitan warrior of the 12th century, and the leader of a group of mercenaries in the service of King Richard I of England.
Richard eulogized Mercadier's exploits in his letters, and gave him the estates left by Ademar de Bainac in Limousin, who died without heirs around 1190.
According to one account, Mercadier avenged his death by storming the castle, hanging the defenders and flaying alive Pierre Basile, the crossbowman who had shot the king, despite Richard's last act pardoning him.
Mercardier features prominently in The Outlaw Chronicles series by Angus Donald, especially books 4 (Warlord) and 5 (Grail Knight), as a major antagonist.
He is portrayed as a ruthless killer and mercenary leader with few or no redeeming qualities, and as the main perpetrator of English atrocities during the 3rd Crusade and King Richard's wars against the French.