State atheism is the official rejection of religion in all forms by a government in favor of atheism. Although many governments throughout history have officially opposed religion (and sometimes persecuted religious leaders), the only country that has ever actually banned religion was Albania under Enver Hoxha.

Distinction between state atheism and secular government

State atheism is not to be confused with anti-clericalism, the effort to reduce the economic and political power of clergy in politics. Neither is it to be confused with religious neutrality, in which a government recognizes the legal necessity of separation of church and state. A state-sponsored religion within a political system implies preferential treatment of one tradition at the expense of others, thus the separation of church and State protects religious minorities. Finally, state atheism is not to be confused with selective persecution of some religious beliefs or their adherents in favor of some other, more dominant religion. State atheism is opposed to all religion equally.

In brief, state atheism implies that the government actively opposes all forms of religion, while secular government implies that the government in question takes a neutral view towards religious matters.