Antoine Sanguin (1493—25 November 1559, Paris) was the uncle of Anne de Pisseleu d'Heilly, mistress of François I, to whom he owed his ecclesiastical career; there is no record of his having taken holy orders.
He was abbot in commendam of the abbey of Fleury-sur-Loire, and Master of the royal chapel of François I. He was elected bishop of Orléans, 6 November 1533, and made a cardinal in the consistory of 19 December 1539, by Pope Paul III, and Grand Aumonier of France, 7 August 1543.
He was made Governor of Paris to defend the city against the threats of Charles V, Holy Roman Emperor, in which capacity he was among the delegates charged with negotiating the peace with the emperor.
At the death of the king in 1547, his position at court was compromised. He resigned his post of almoner and retired to Italy, where in Rome he participated in the conclave of 1549-50. In 1550 he was rehabilitated, returned to France, and appointed archbishop of Toulouse by the new king, Henri II.