Jordan IV (died 1288) was the Lord of L'Isle-Jourdain and a vassal of Alfonso of Poitou.
His son-in-law was Aimery IV of Narbonne, who led the armies of Florence and Anjou in the Battle of Campaldino in 1289 and his brother was the provost of Toulouse.
Sometime before his activities in Italy Jordan (Jourdan in contemporary Occitan) participated in a torneyamen, a poetical tournament, with Guiraut Riquier, Raimon Izarn, and Paulet de Marseilla.
In 1266, after drawing up a will, he brought a contingent of knights and crossbowmen to Italy with him in support of Charles of Anjou.
He was praised by Pope Clement IV and enfeoffed in the Principate and Calabria by Charles, but he soon returned to Gascony.