Hair is predominantly a proteinaceous fiber that originates from hair follicles located within the subcutis and/or dermis of the skin. It is one of the defining features of mammals, serving important functions, such as thermoregulation and endothermy. Among mammals, humans are exceptional in lacking a full covering of body hair. Instead the growth of terminal hairs is limited to specific body regions, such as the scalp, axillae, and groin. Our aim in this chapter is to provide an overview of the anthropology of human scalp hair. We will explore approaches to the study of variation in human scalp hair phenotypes, as well as the genetic and evolutionary basis of this diversity. The biology of human scalp hair, with emphasis on quantitative and qualitative differences among populations, as well as impact on hair grooming practices will also be discussed.