Objectives: The study aimed to investigate the sleep quality of aged people in Tabriz and identify its associated factors. Design: Cross-sectional study. Setting(s): Tabriz, the capital of the East Azerbaijan province in northwest Iran. Participants: A total of 1362 participants were selected from a representative sample of community-dwelling older people aged≥60 years who were living in Tabriz, using the probability proportional to size (PPS) sampling method. Outcome measures: Blood pressure (BP), sleep quality, depression, anxiety, loneliness, physical activity, daily activities, living independently, and social support were assessed using a standard mercury sphygmomanometer, Pittsburgh Sleep Quality Index (PSQI), Hospital Anxiety and Depression Scale (HADS), the 6-item De Jong Gierveld Loneliness Scale, Physical Activity Scale for the Elderly (PASE), Activity of Daily Living (ADL), Instrumental Activity of Daily Living (IADL), respectively. Results: The mean score of total PSQI was 5.39±2.91. The multivariable logistic regression model showed that being female (Odds ratio [OR]=1.68, 95% confidence interval [CI]=1.29 to 2.18), hypertensive (OR=2.12, 95% CI=1.52 to 2.95), diabetes mellitus (DM) (OR=1.29, 95% CI=0.96 to 1.72), abnormal anxiety level (OR=2.38, 95% CI=1.67 to 3.38), and low PASE score (OR=0.99, 95% CI=0.99 to 1) were significantly associated with a higher risk of poor sleep quality. Conclusions: Low physical activity is a modifiable risk factor for low sleep quality in older adults. Hence, the development of physical activity programs can be effective in improving sleep quality. Furthermore, women are the priority in designing interventions.