Biculturalism in sociology involves two originally distinct cultures in some form of co-existence.

A policy recognizing, fostering or encouraging biculturalism typically emerges in countries that have emerged from a history of national or ethnic conflict in which neither side has gained complete victory. This condition usually arises as a consequence of settlement by colonists. Resulting conflicts may take place either between colonisers and indigenous peoples (as in Fiji) and/or between rival groups of colonisers (note the case of South Africa). A deliberate policy of biculturalism influences the structures and decisions of governments to ensure that they allocate political and economic power and influence equitably between people and/or groups identified with the opposite sides of the cultural divide.

Examples include the conflicts between Anglophone and Francophone Canadians, between Māori and Pākehā New Zealanders and between Anglophone White South Africans and Boers.

The term biculturalism was originally adopted in the Canadian context. Because the word "biculturalism" suggests, more or less explicitly, that only two cultures merit formal recognition, advocates of multiculturalism (for which it formed a precedent) may regard bicultural outlooks as inadequately progressive in comparison.

In the context of relations between the cultures of deafness and non-deafness, people find the word "biculturalism" less controversial because the distinction (between spoken language and sign language) commonly seems like a genuine binary distinction — transcending the distinctions between various spoken languages.

In the context of the United States of America, bicultural distinctions have traditionally existed between America and Mexico, and between the White and the African American population of the United States.

As different cases of biculturalism with some sort of formal recognition, note:

• Belgium, divided basically between speakers of French and of Dutch
• Vanuatu, formerly a condominion with both French and British politico-administrative traditions
• the Polish–Lithuanian Commonwealth, retrospectively termed "The Commonwealth of Both Peoples"
• Switzerland, overwhelmingly German and French in language (though with recognition of Italian and Romansch)
• Paraguay, with a population 90% of which speaks Guaraní and 75% of which speaks Spanish