A demigod is a mythological being with more power than a mortal but less than a god. In mythology, a demigod is a less important god, especially one who is half god and half human. The term "demigod" can also refer to a person so outstanding as to seem to approach the divine. In mythology and modern fiction, a demigod is the offspring of a deity with a mortal. The English term "demi-god" is a calque of the Latin word semideus, which means "half-god". The concept of a demigod did not have a consistent definition in the ancient Greek and Roman world, and associated terminology rarely appeared. The first Roman to employ the term "demigod" may have been the poet Ovid, who used the Latin semideus several times in reference to minor deities.

Examples of demigods in mythology and modern fiction include Hercules, who is the son of Zeus in the DC Universe, and Goro, who is the demigod son of Oharu and Mahiruma in the anime spin-off of Inuyasha, Yashahime: Princess Half-Demon. Demigods are also important figures in Rick Riordans Percy Jackson series.