Hapa is a Hawaiian word for someone of multiracial ancestry. In Hawaii, the word refers to any person of mixed ethnic heritage, regardless of the specific mixture. The term is used for any multiracial person of partial East Asian, Southeast Asian, or Pacific Islander mixture in California. In what can be characterized as trans-cultural diffusion or the wave model, this latter usage has also spread to Massachusetts, Ohio, and Oregon.

The terms multiracial people or mixed-race people refer to people who are of more than one race, and the terms multi-ethnic people or ethnically mixed people refer to people who are of more than one ethnicity. A variety of terms have been used both historically and presently for mixed-race people in a variety of contexts, including multiethnic, polyethnic, occasionally bi-ethnic, Métis, Muwallad, Melezi, Coloured, Dougla, half-caste, ʻafakasi, mestizo, mutt, Melungeon, quadroon, octoroon, sambo/zambo, Eurasian, hapa, hāfu, Garifuna, pardo, and Gurans. A number of these once-acceptable terms are now considered offensive, in addition to those that were initially coined for pejorative use.