Joan of Ponthieu, Dame of Epernon

Jeanne de Ponthieu, dame d'Épernon, Countess of Vendôme and of Castres, better known in English as Joan of Ponthieu, was a French vassal; she was Dame d'Épernon suo jure by inheritance from 1343 to 1376. She was the youngest daughter of Jean II de Ponthieu, Count of Aumale. She was Countess of Vendôme and of Castres as the wife of Jean VI de Vendôme, Count of Vendôme and of Castres. She acted as regent for her infant granddaughter Jeanne, suo jure Countess of Vendôme from 1371 until the child's premature death in 1372.