Children's neighborhood contexts are defined by rising socioeconomic inequality and segregation. This article reviews several decades of research on how neighborhood socioeconomic conditions are associated with children's development. The nonexperimental literature suggests that the most salient neighborhood socioeconomic condition depends on the outcome—disadvantage for social, emotional, and behavioral outcomes and advantage for achievement-related outcomes. Moreover, children's cumulative exposure to neighborhood socioeconomic conditions over the first two decades of life, and possibly especially in childhood, may matter most for later development. These findings are partially supported by the few experimental studies available, and across study designs, neighborhood effects are typically modest. In order to improve our understanding of this topic, we recommend methodologically rigorous designs—experimental and nonexperimental—and comparative approaches, particularly ones addressing the complexities of development in neighborhood contexts. To guide this research, we provide an integrated framework that captures a broad and dynamic perspective including macro forces, neighborhood social processes and resources, physical features, spatial dynamics, and individual differences.