Study Objectives: To investigate the associations of specifc neighborhood features (disorder, safety, social cohesion, physical environment, and socioeconomic status) with sleep duration and quality. Design: Cross-sectional. One wave of a population-based study (Multi-Ethnic Study of Atherosclerosis). Setting: Community-dwelling participants in New York, NY and Los Angeles, CA. Participants: There were 1,406 participants (636 males, 770 females). Interventions: NA. Measurements and Results: Sleep was assessed using reported hours of sleep, the Epworth Sleepiness Scale, and insomnia symptoms. Neighborhood characteristics were assessed via questionnaires administered to neighbors of study participants and were aggregated to the neighborhood (census tract) level using empirical Bayes estimation. An adverse social environment (characterized by high disorder, and low safety and social cohesion) was associated with shorter sleep duration after adjustment for the physical environment, neighborhood and individuallevel socioeconomic status (SES), and other short sleep risk factors (mean difference per standard deviation increase in summary social environment scale 0.24 h 95% confdence interval 0.08, 0.43). Adverse neighborhood social and physical environments, and neighborhood SES were associated with greater sleepiness, but associations with physical environments were no longer statistically signifcant after adjustment for sociodemographic characteristics. Neighborhood SES was a weaker and less consistent predictor of specifc measures of neighborhood social and physical environments. Neighborhood characteristics were not associated with insomnia. Conclusions: Shortened sleep related to adverse social environments represents one potential pathway through which neighborhoods may.