In some countries, some people say, that humans eat whale meat is tradition. Is whale meat halal as human food?
Narrated Abu Hurayrah:
A man asked the Messenger of Allah (ﷺ): Messenger of Allah, we travel on the sea and take a small quantity of water with us. If we use this for ablution, we would suffer from thirst. Can we perform ablution with sea water? The Messenger (ﷺ) replied: Its water is pure and what dies in it is lawful food.
Sunan Abi Dawud 83
Allah also says in the Quran:
Lawful to you is game from the sea and its food as provision for you and the travelers, but forbidden to you is game from the land as long as you are in the state of ihram. And fear Allah to whom you will be gathered. Quran 5:96
Most purely aquatic life is considered Halal. There is debate on amphibians but w.r.t your question whale is a purely aquatic creature that is considered Halal.