Alexander I Balas (), was the ruler of the Greek Seleucid kingdom in 150–146 BC. Alexander defeated Demetrius Soter for the crown in 150 BC. Ruling briefly, he lost the crown to Demetrius II Nicator during his defeat at the Battle of Antioch (145 BC) in Syria, dying shortly after. He is the title character of the oratorio Alexander Balus, written in 1747 by George Frideric Handel.