Is it legal to be atheist?

Answer 1

Yes, it is legal in most countries to be an atheist, although you may need to use caution before announcing this in some circles. If it were not legal to be an atheist, that would surely constitute religious discrimination, even persecution. Thankfully, the days of mandatory belief in Christianity are long gone.

Answer 2

It depends on the country. It is not illegal in most Western countries. It is also strongly advocated in Irreligious and Communist countries. However, in many countries in Africa, the Islamic World, and the Philippines, being an Atheist is either illegal or is socially unacceptable to the point where violence will be manifest against you for "declaring" your Atheism. Particularly religious parts of the United States show similar social opprobrium towards Atheists.