What king of Judah sacrificed his children to pagan gods?

King Ahaz

"In the seventeenth year of the reign of Pekah son of Remaliah, Jotham’s son Ahaz became king over Judah. Ahaz was twenty years old when he began to reign, and he reigned for sixteen years in Jerusalem. He did not do what pleased the Lord his God, in contrast to his ancestor David. He followed in the footsteps of the kings of Israel. He passed his son through the fire, a horrible sin practiced by the nations whom the Lord drove out from before the Israelites. He offered sacrifices and burned incense on the high places, on the hills, and under every green tree."
-- 2 Kings 16:1-4

Yes it was