The hero famous for his quest for the Golden Fleece in Greek mythology is Jason. He leads the Argonauts on a perilous journey to retrieve the fleece from the enchanted land of Colchis. Jason's adventure is marked by trials and the assistance of Medea, a sorceress who aids him in overcoming obstacles. This quest embodies themes of heroism, loyalty, and betrayal, illustrating the complexities of human emotions within mythological narratives.