Thor, in Norse mythology, the god of thunder, eldest son of Odin, ruler of the gods, and Jord, the earth goddess. Thor was the strongest of the Aesir, the chief gods, whom he helped protect from their enemies, the giants. He had a magic hammer, which he threw with the aid of iron gloves and which always returned to him. Thunder was supposed to be the sound of the rolling of his chariot. Thursday is named for Thor.