Emperor Itoku (懿徳天皇) was the fourth imperial ruler of Japan to appear on the traditional list of emperors. No firm date can be assigned to this emperor and he is regarded by historians as a "legendary emperor". He was the third one of eight emperors without legend. In Kojiki and Nihonshoki only his name and geneology were recorded. His historical existence were believed traditionally and a tomb was attributed to him. But contemporary studies support the view no such person existed.

His posthumous name literally means "benign virtue."