Philip I of Savoy-Achaea

Philip I of Savoy-Achaea (1278–25 September 1334) was lord of Piedmont and founder of the Savoy-Achaea branch. Son of Thomas III of Piedmont, he was a ward of his uncle Amadeus V of Savoy, who held his inheritance until an arbitration gave him Piedmont as a Savoyard fief.

In 1301 he married Isabella of Villehardouin, Princess of Achaea, and ruled the Morea. His appointment of followers from Savoy and Piedmont aroused the local barons' resentment, and Charles II of Naples deposed him in 1307. By Catherine de la Tour du Pin he had his heir James. He died at Pinerolo.