Racial residential segregation is a fundamental cause of racial disparities in health. Despite the absence of supportive legal statutes, residential segregation remains extremely high for most African Americans in the United States. Segregation determines access to education and employment opportunities, which in turn shape socioeconomic status (SES) and significantly influence health outcomes. The authors argue that effective efforts to eliminate racial disparities in health must address segregation and its pervasive consequences. They review evidence that suggests segregation is a primary cause of racial differences in SES and health, creating conditions inimical to health in both the social and physical environment. The article also discusses the nature and origins of residential segregation, its impact on educational and employment opportunities, and the resulting racial differences in SES. Additionally, it explores how segregation affects neighborhood quality, health behaviors, access to medical care, and social context, contributing to persistent racial disparities in health. The conclusion emphasizes the need to tackle residential segregation to effectively reduce racial disparities in health.Racial residential segregation is a fundamental cause of racial disparities in health. Despite the absence of supportive legal statutes, residential segregation remains extremely high for most African Americans in the United States. Segregation determines access to education and employment opportunities, which in turn shape socioeconomic status (SES) and significantly influence health outcomes. The authors argue that effective efforts to eliminate racial disparities in health must address segregation and its pervasive consequences. They review evidence that suggests segregation is a primary cause of racial differences in SES and health, creating conditions inimical to health in both the social and physical environment. The article also discusses the nature and origins of residential segregation, its impact on educational and employment opportunities, and the resulting racial differences in SES. Additionally, it explores how segregation affects neighborhood quality, health behaviors, access to medical care, and social context, contributing to persistent racial disparities in health. The conclusion emphasizes the need to tackle residential segregation to effectively reduce racial disparities in health.