Isabelle de Chalon-Arlay
Isabelle de Chalon-Arlay (c. 1292–c. 1359) was the daughter of Jean I, lord of Chalon-Arlay, and Marguerite of Burgundy. In 1309 she married Louis II of Savoy, baron of Vaud, allying his house with the leading nobility of the Franche-Comté.
Her son Jean died fighting at Laupen in 1339, and her daughter Catherine was named Louis's heiress in his 1340 testament. When Louis died in 1349, Isabelle ruled the barony of Vaud jointly with Catherine.