Jean de Poitiers, seigneur de Saint Vallier (c. 1475 – 1539) was a French nobleman best known as the father of Diane de Poitiers. He was the son of Aymar de Poitiers and Jeanne de La Tour d'Auvergne. He was implicated in a plot against King Francis I of France, discovered by his son-in-law Louis de Brézé, seigneur d'Anet, and was condemned to death, but reprieved by the king. He was imprisoned in the French castle of Loches where he died very quickly. His story was the inspiration for a character in Victor Hugo's 1832 play Le roi s'amuse who became Count Monterone when Francesco Maria Piave and Giuseppe Verdi relocated the plot of their 1851 opera Rigoletto from France to the Duchy of Mantua.