The noble Breton family line of Porhoët was a French noble family in the middle ages, from around 990 through the 1200's. Notable members included Odo I, Odo II, and Alan I. Alan I would go on to form the Franco-Breton House of Rohan, which survives to the modern day.

Yolande of Brittany, also known as Yolande de Dreux, was the ruler of the counties of Penthièvre and Porhoet in the Duchy of Brittany. Yolande had been betrothed to King Henry III of England in 1226 at the age of seven years, but married Hugh XI of Lusignan, the half-brother of Henry III. Through Hugh, she became Countess of La Marche and of Angoulême. She was the mother of seven children. From 1250 to 1256, she acted as Regent of La Marche and Angoulême for her son, Hugh XII of Lusignan.