Purpose: The purpose of this study was to identify the influence of physical activity and depression on sleep quality among the young-old and old-old community-dwelling elderly. Methods: Participants were 216 community-dwelling older adults in Korea aged 65 or above. Data were collected using structured questionnaires with face-to-face interviews that included demographic and health-related characteristics, International Physical Activity Questionnaires (IPAQ), the Short Form Geriatric Depression Scale (SGDS) and the Pittsburgh Sleep Quality Index (PSQI). A hierarchical multiple regression was conducted to examine whether physical activity and depression would predict sleep quality under other controlled factors. Results: There were differences in demographic and health-related characteristics, physical activity, and depression by age groups, but not in sleep quality. In the young-old elderly, physical activity (β=-0.22, p=.043) and depression (β=0.31, p=.002) were significantly associated with sleep quality (F=4.46, p=.001, Adjusted R2=.16). In the old-old elderly, physical activity (β=-0.29, p=.001) and depression (β=0.41, p<.001) were significantly associated with sleep quality (F=10.79, p<.001, Adjusted R2=.29). Conclusion: These finding highlight physical activity and depression as important contributors to sleep quality in both young-old and old-old elderly.