Hasmonean (Maccabean) Hellenized king of Judaea (104–103 BC).

The son of Hyrcanus I, he broke his late father's will and seized the throne from his mother and jailed or killed his brothers. According to the historian Josephus, Aristobulus conquered the Ituraeans of Lebanon and forcibly converted them to Judaism. He was the first of his house to adopt the title of king (basileus).