The terms multiracial and mixed-race describe people whose ancestries come from multiple races. Unlike the term biracial, which often is only used to refer to having parents or grandparents of two different races, the term multiracial may encompass biracial people but can also include people with more than two races in their heritage, or also may refer to the origin of more generationally distant genetic admixtures of more than one race in a person's DNA.

The actual incidence of multiracial admixture and heritage is believed to be far higher than is commonly reported, although there is evidence that this is changing as people become more comfortable with revealing personal multiracial heritage. Census records and other studies also show the real number of multiracial individuals to be increasing in the United States along with an increase in marriages across race lines. Other surveys also reflect this trend in many modern nations. The term "multiracial" may also be used to refer to groups or populations where individuals of more than one race are counted as a part of a whole group. In this sense of the word, "multiracial" refers to a racially heterogeneous rather than a homogeneous group or population.