Ōtenta (大典太) is a Japanese sword specified for National Treasures of Japan. It is one of the five swords under heaven (天下五剣) and was a treasure of the Ashikaga shogunate. After the Ashikaga shogunate had fallen, it was succeeded by the Maeda clan.
The sword was made in a style unlike those of other swords from the same era. Because of this difference in quality, it was regarded a spiritual blade able to cure illnesses if left at someone's bedside.