Elijah or Elias pronounced /ɨˈlaɪ.əs/, Hebrew: אליהו, Eliyahu; Arabic:إلياس, Ilyās), whose name (El-i Yahu) means "Yahweh is my God" according to the Books of Kings was a prophet in the Kingdom of Israel during the reign of Ahab (9th century BCE).

According to the Books of Kings, Elijah defended the worship of Yahweh over that of the more popular Baal, he raised the dead, brought fire down from the sky, and ascended into heaven in a whirlwind (either accompanied by a chariot and horses of flame or riding in it). In the Book of Malachi, Elijah's return is prophesied "before the coming of the great and terrible day of the Lord," making him a harbinger of the Messiah and the eschaton in various faiths that revere the Hebrew Bible. Derivative references to Elijah appear in the Talmud, Mishnah, the New Testament, and the Qur'an.

In Judaism, Elijah's name is invoked at the weekly Havdalah ritual that marks the end of Shabbat, and Elijah is invoked in other Jewish customs, among them the Passover seder and the Brit milah (ritual circumcision). He appears in numerous stories and references in the Haggadah and rabbinic literature, including the Babylonian Talmud.

In Christianity, the New Testament describes how both Jesus and John the Baptist are compared with Elijah, and on some occasions, thought by some to be manifestations of Elijah, and Elijah appears with Moses during the Transfiguration of Jesus.

In Islam, the Qur'an describes Elijah as a great and righteous prophet of God, and one who powerfully preached against the worship of Ba'al.

Elijah is also a figure in various folkloric traditions. In Macedonia, Serbia, Bulgaria, and Romania, he is known as "Elijah the Thunderer" and in folklore is held responsible for summer storms, hail, rain, thunder, and dew.