Hervé IV of Donzy (1173–1223) was a French nobleman and participant in the Fifth Crusade. By marriage in 1200 to Mahaut de Courtenay (1188–1257), daughter of Peter II of Courtenay, he became Count of Nevers. In a dispute over the château de Gien with Peter of Courtenay, Hervé came to a settlement in 1199, having defeated and captured his overlord Peter at Cosne-sur-Loire. After Peter's death in 1219, he became Count of Auxerre and Tonnerre also; with Philip II, Marquis of Namur and Robert de Courtenay contesting Auxerre. He acquired Liernais also, in 1210.