Which prophet was swallowed by a big fish?

 Prophet Yūnus (Jonah, عليه السلام) was sent by Allah to the people of Nineveh (near present-day Iraq).

He called them to worship Allah alone, but they rejected his message.

Out of frustration, Yūnus (عليه السلام) left his people before Allah gave him permission to do so.

He boarded a ship, but during a storm, lots were drawn, and his name was chosen to be thrown overboard.

Yūnus (عليه السلام) was then swallowed by a huge fish (whale) by Allah’s command.

In the belly of the fish, he realized his mistake and made the famous du‘ā:

لَا إِلٰهَ إِلَّا أَنتَ سُبْحَانَكَ إِنِّي كُنتُ مِنَ الظَّالِمِينَ

“There is no god but You, Glory be to You, indeed I was of the wrongdoers.”

(Surah Al-Anbiya 21:87)

Allah forgave him and caused the fish to release him safely on the shore.

When he returned to his people, he found that they had repented and believed, so Allah spared them from punishment.