A god worshipped by the Philistines in the ancient city of Ekron. In 852 BC, when King Ahaziah of Israel got hurt falling from his balcony, he sent people to ask Baal-zebub if he would get better (2 Kings 1:2). The prophet Elijah was very angry about this. He said the king would die because he didn't respect Israel's God.
We're not sure exactly what Baal-zebub was the god of. His name means "lord of the flies." Maybe people thought he could tell the future by watching flies, or that he protected people from lots of flies. Archeologists have found small golden fly statues where the Philistines lived.
Many experts think the name Baal-zebub was actually changed from Baal-zebul, which means "Baal the prince." They think the Israelites changed the name on purpose to make fun of this god.