Judah (Hebrew: יְהוּדָה‎, Modern: Yəhūda, Tiberian: Yŭhūḏā) was, according to the Book of Genesis, the fourth of the six sons of Jacob and Leah and the founder of the Tribe of Judah of the Israelites. By extension, he is indirectly the eponym of the Kingdom of Judah, the land of Judea, and the word Jew.

According to the narrative in Genesis, Judah alongside Tamar is the patrilineal ancestor of the Davidic line. The Tribe of Judah features prominently in Deuteronomistic history, which most scholars agree was reduced to written form, although subject to exilic and post-exilic alterations and emendations, during the reign of the Judahist reformer Josiah from 641 to 609 BCE. According to the Christian narrative, he was the ancestor of Jesus.