Baldur, Or Balder, in northern mythology, the son of Odin and Frigga, and the most beautiful and beloved of the gods of Odin's race. He was the husband of Nanna and the father of Forseti. His home was in Breidablik, the most beautiful part of Asgard, the northern Olympus. Baldur having long been troubled by dreams and evil omens, indicating danger to his life, his mother travelled through the whole universe, eliciting from every created tiling a promise not to injure the god. She only neglected to ask this from the mistletoe, which seemed to her entirely harmless. Loki, the most deceitful among the gods, and an enemy of Baldur, remarked this omission, and cut from the mistletoe a piece for the point of a dart. The other gods, surrounding Baldur, made proof of his invulnerability, in sport, by casting at him their weapons, with stones and clubs of wood; but nothing injured him. Then Loki approached and induced the blind god Hodur to throw the dart he had made from the forgotten mistletoe. Baldur was pierced by it and killed. The gods, lamenting his loss, sent his brother Hermodur to Hel, the under world, to ask upon what condition the goddess of the dead would release him. The reply was that he could only be spared if everything in the world would weep for him.

All consented except Loki, who had disguised himself as a giantess. The gods then celebrated Baldur's funeral with the greatest pomp. His body was carried to the seashore and burned on his great ship Hinghorni, which was lifted out of the sea by the aid of the giantess Hirrokin. Nanna died of grief, and her body was burned with his. By the ancient Germans Baldur was worshipped as the god of peace; other northern nations seem also to have imagined him as a deity similar to the Greek Apollo.