Objectives/Goals: Sleep is a useful intervention target to improve mental and physical health. Yet, the contextual factors that impact sleep in real-life settings are poorly understood. We assessed how psychological and socioenvironmental factors influence self-reported sleep in a large, US sample (Study 1) and sleep physiology in a prospective cohort (Study 2). Methods/Study Population: Study 1: 13,483 participants (63% males, mean age 46, 24% non-White) completed on-demand blood pressure (BP), self-reported stress, physical health, and sleep duration assessments for 3 weeks. Study 2: 42 Black adults (23% males, mean age 42) completed up to six ambulatory sleep recordings at home for 2 weeks. Stage durations for rapid eye movement (REM) and non-REM Stages 1, 2, and 3 were determined. Daily self-reports of stress and physical health were also gathered. For both studies, residence zip codes were linked to a national database to quantify neighborhood factors (i.e., built environment, poverty, social cohesion, etc.). Multiple linear regressions and mixed-effect models assessed whether neighborhood factors, demographics, health indices, and stress could predict sleep durations. Results/Anticipated Results: In Study 1, neighborhood disadvantage, perceived stress, and systolic BP were associated with shorter sleep durations. Better self-reported health predicted longer sleep durations. Black, Native, Latino/as, and Pacific Islander participants had shorter sleep durations, whereas White participants had longer sleep durations. An interaction between perceived stress intensity and health indicated that better health (+1SD) protected sleep from increasing stress. Preliminary analyses in 26 participants from Study 2 revealed that neighborhood disadvantage and self-reported poor health are associated with shorter Stage 2 sleep durations. However, daily stress did not predict stage durations, and no interactions emerged. Discussion/Significance of Impact: Neighborhood disadvantage led to short sleep in two studies, with novel findings indicating that Stage 2 durations may be most sensitive to structural disadvantage. Interventions that invest in material resources to reduce neighborhood inequities may be an innovative approach to protect sleep and mitigate related illness.