Cultural homogenization refers to the process by which different cultures become more similar to each other as globalization progresses. It is an aspect of cultural globalization and refers to the reduction in cultural diversity through the popularization and diffusion of a wide array of cultural symbols, including physical objects, customs, ideas, and values. The process of cultural homogenization can impact national identity and culture, which would be "eroded by the impact of global cultural industries and multinational media".

Cultural homogenization can take place both at a local and global level. At a local level, it can be interpreted as assimilation, which refers to the loss of cultural characteristics of a community, which is often an immigrant community, in favor of the dominant cultural norms and values. On a global level, cultural homogenization mostly refers to the increasing dominance of American popular culture in favor of local cultures.

While some scholars argue that as a result of globalization we are going through cultural homogenization, others use the concept of cultural heterogenization. In contrast with homogenization which refers to the process of becoming similar, heterogenization refers to differentiation.

Cultural homogenization is often criticized as a form of cultural imperialism and neo-colonialism, especially in the context of Western culture dominating and destroying other cultures. The process of cultural homogenization in the context of the domination of the Western (American), capitalist culture is also known as McDonaldization, coca-colonization, Americanization, or Westernization.

Overall, homogenization of culture is a process of blurring the differences between the elements of "higher" and "lower" culture. Homogenization results in homogeneity - unification, similarity of elements or homogeneity. It has developed to a large extent due to the development of mass production, commercialization, globalization, and the massification of symbolic culture.