Peter I of Alencon (b. 1251 in Holy Land - d. April 6, 1284 in Salerno, Italy) was the son of Louis IX of France and Margaret of Provence. He became Count of Alençon in 1269 and in 1284, Count of Blois and Chartres, and Seigneur de Guise in 1272 and 1284. He was also Count of Perche.He was born in the Holy Land while his father headed the Seventh Crusade.