Philip I, also known as Philip of Saint Pol (25 July 1404 – Leuven, 4 August 1430), was the younger son of Antoine, Duke of Brabant and Jeanne of Saint-Pol. He succeeded his brother John IV as Duke of Brabant in 1427, while he had inherited Saint-Pol and Ligny as an appanage on the death of his maternal grandfather, Waleran III of Luxembourg, Count of Ligny, in 1415.