Scientific racism, sometimes termed biological racism, is the pseudoscientific belief that the human species can be subdivided into biologically distinct taxa called "races", and that empirical evidence exists to support or justify racism, racial inferiority, or racial superiority. Before the mid-20th century, scientific racism was accepted throughout the scientific community, but it is no longer considered scientific. The division of humankind into biologically separate groups, along with the assignment of particular physical and mental characteristics to these groups through constructing and applying corresponding explanatory models, is referred to as racialism, race realism, or race science by those who support these ideas. Modern scientific consensus rejects this view as being irreconcilable with modern genetic research.

Race is a categorization of humans based on shared physical or social qualities into groups generally viewed as distinct within a given society. The term came into common usage during the 16th century, when it was used to refer to groups of various kinds, including those characterized by close kinship relations. By the 17th century, the term began to refer to physical (phenotypical) traits, and then later to national affiliations. Modern science regards race as a social construct, an identity which is assigned based on rules made by society. While partly based on physical similarities within groups, race does not have an inherent physical or biological meaning. The concept of race is foundational to racism, the belief that humans can be divided based on the superiority of one race over another.