Who was the father of Ahab's wife Jezebel?

Answer: Ethbaal king of the Sidonians

Ahab married Jezebel the daughter of Ethbaal king of the Sidonians, and went on to serve and worship Baal.

“And as if it were not enough for him to walk in the sins of Jeroboam son of Nebat, he even married Jezebel the daughter of Ethbaal king of the Sidonians, and he then proceeded to serve and worship Baal.”— 1 Kings 16:31 (BSB)