Gerald I, Count of Armagnac

Gerald I Trancaleon (also spelled Guiraut or, in French, Géraud Trancaléon or Tranche-Lion) (died 1020) was the Count of Armagnac from 995 until his death. He was the son and successor of Bernard I.

He married Adalais, daughter of William V of Aquitaine and his second wife Prisca, heiress of Gascony. He had a daughter, Galdis, who inherited the viscounty of Corneilhas and married Adhemar of Polestron. He also had a son, Bernard, who succeeded him in Armagnac and later received Gascony through his grandmother.