Which old nurse recognizes Odysseus by his scar?

The old nurse who recognizes Odysseus by his scar is Eurycleia.

In Book 19 of the Odyssey, Odysseus returns to Ithaca disguised as a beggar. Penelope orders the elderly nurse Eurycleia to wash the stranger’s feet. As she touches his leg, she recognizes a distinctive scar and realizes that the supposed beggar is her long-absent master.

The scar was made when Odysseus was young. During a boar hunt on Mount Parnassus with his maternal grandfather Autolycus and Autolycus’s sons, a wild boar gored him. Homer pauses the recognition scene to recount this earlier event, making the scar a physical link between the hero’s childhood and his disguised return.

Eurycleia is Odysseus’s wet nurse and later nurses his son Telemachus. She is the only person in the household who identifies Odysseus without his first revealing himself. Odysseus immediately warns her to keep silent, because he is preparing to confront Penelope’s suitors. She later helps identify the servant women who have betrayed Penelope, while Penelope herself requires a separate test involving the couple’s immovable marriage bed.