Cultural diversity is the quality of diverse or different cultures, as opposed to monoculture, as in the global monoculture, or a homogenization of cultures, akin to cultural decay. The phrase cultural diversity can also refer to having different cultures respect each other's differences. The phrase "cultural diversity" is also sometimes used to mean the variety of human societies or cultures in a specific region, or in the world as a whole. The culturally destructive action of globalization is often said to have a negative effect on the world's cultural diversity.

By analogy with biodiversity, which is thought to be essential to the long-term survival of life on earth, it can be argued that cultural diversity may be vital for the long-term survival of humanity; and that the conservation of indigenous cultures may be as important to humankind as the conservation of species and ecosystems is to life in general. The General Conference of UNESCO took this position in 2001, asserting in Article 1 of the Universal Declaration on Cultural Diversity that "...cultural diversity is as necessary for humankind as biodiversity is for nature"[2]
This position is rejected by some people, on several grounds. Firstly, like most evolutionary accounts of human nature, the importance of cultural diversity for survival may be an un-testable hypothesis, which can neither be proved nor disproved. Secondly, it can be argued that it is unethical deliberately to conserve "less developed" societies, because this will deny people within those societies the benefits of technological and medical advances enjoyed by those of us in the "developed" world.
In the same manner that the promotion of poverty in underdeveloped nations as "cultural diversity" is unethical, it is similarly unethical to promote all religious practices simply because they are seen to contribute to cultural diversity.