Gerald V d'Armagnac (died 1219), Count of Armagnac and Fézensac from 1215 to 1219, was the son of Bernard d'Armagnac, Viscount of Fézensaguet and Geralda of Foix.
[1] In 1182, his great uncle the Count Bernard IV of Armagnac, made Gerald's father, Bernard, heir in case he died without children.
On 8 June 1215, to avoid the fate of Count Raymond VI of Toulouse, he acknowledged Simon de Montfort as overlord.
In 1217, Count Raymond VI rebelled against Simon de Montfort.
Some historians and genealogists, including the famous Pere Anselme de Sainte-Marie, confuse him with Gerald IV.