Background: Sleep is essential to health and affected by environmental and clinical factors. There is limited longitudinal research examining sleep quality in homeless older adults. Objective: To examine the factors associated with poor sleep quality in a cohort of older adults in Oakland, California recruited while homeless using venue-based sampling and followed regardless of housing status. Design: Longitudinal cohort study. Participants: 244 homeless-experienced adults aged ≥ 50 from the Health Outcomes in People Experiencing Homelessness in Older Middle Age (HOPE HOME) cohort. Main Measures: We assessed sleep quality using the Pittsburgh Sleep Quality Index (PSQI). We captured variables via biannual questionnaires and clinical assessments. Key Results: Our sample was predominantly men (71.3%), Black (82.8%), and had a median age of 58.0 years old (IQR 54.0, 61.0). Two-thirds of participants (67.2%) reported poor sleep during one or more study visits; sleep duration was the worst rated subdomain. In a multivariable model, having moderate-to-severe depressive symptoms (AOR 2.03, 95% CI 1.40–2.95), trouble remembering (AOR 1.56, 95% CI 1.11–2.19), fair or poor physical health (AOR 1.49, 95% CI 1.07–2.08), two or more chronic health conditions (AOR 1.76, 95% CI 1.18–2.62), any ADL impairment (AOR 1.85, 95% CI 1.36–2.52), and being lonely (AOR 1.55, 95% CI 1.13–2.12) were associated with increased odds of poor sleep quality. Having at least one confidant was associated with decreased odds of poor sleep (AOR 0.56, 95% CI 0.37–0.85). Current housing status was not significantly associated with poor sleep quality. Conclusions: Homeless-experienced older adults have a high prevalence of poor sleep. We found that participants' physical and mental health was related to poor sleep quality. Poor sleep continued when participants re-entered housing. Access to physical and mental healthcare, caregiving support, and programs that promote community may improve homeless-experienced older adults sleep quality, and therefore, their overall health. [ABSTRACT FROM AUTHOR]