Which prophet married a prostitute as a symbol?

Answer: Hosea

The LORD told Hosea, "Go, take a prostitute as your wife," picturing Israel's unfaithfulness; he married Gomer.

“When the LORD first spoke through Hosea, He told him, “Go, take a prostitute as your wife and have children of adultery, because this land is flagrantly prostituting itself by departing from the LORD.” So Hosea went and married Gomer daughter of Diblaim, and she conceived and bore him a son.”— Hosea 1:2-3 (BSB)