BackgroundThe growing population of older adults worldwide is associated with an extended life expectancy and an increasing proportion of older adults with dynapenia. Most research on dynapenia has involved only populations of older adults living in the community; little research has examined the effects of risk factors on sleep quality among older adults with dynapenia residing in assisted living facilities.AimThis study examined the relationships among physical function, nutrition, cognitive function, depression, and sleep quality among older adults with dynapenia residing in assisted living facilities.MethodsIn this cross-sectional study, data on physical function, nutrition, cognitive function, depression, and sleep quality was collected from 178 older adults with dynapenia residing in assisted living facilities, who were selected using purposive sampling. Descriptive statistical analysis, independent-samplettests, chi-squared tests, and logistic regression analysis were performed using SPSS 25.0.ResultsThe statistical analyses revealed correlations between sleep quality and age (t= 2.37,p< 0.05), level of education (χ2= 3.85,p< 0.05), grip strength (t= 3.40,p< 0.01), activities of daily living (t= 4.29,p< 0.001), instrumental activities of daily living (t= 2.23,p< 0.001), calf circumference (t= 2.89,p< 0.01), Mini Nutritional Assessment scores (t= 2.29,p< 0.05), Mini Mental State Exam (MMSE) scores (t= 4.50,p< 0.001), and Geriatric Depression Scale (GDS) scores (t= − 4.20,p< 0.001). Calf circumference (OR = 0.8, 95% CI = 0.650.97,p< 0.05), GDS score (OR = 1.42, 95% CI = 1.05–1.92,p< 0.05), and MMSE score (OR = 0.85, 95% CI = 0.73–0.97,p< 0.05) were related to sleep quality among the sample population.ConclusionPhysical function, nutrition, cognitive function, and depression affect the sleep quality of older adults with dynapenia residing in assisted living facilities. Facility nurses must regularly assess these aspects of their patients to ensure that facility-dwelling older adults can maintain their physical function and improve their health to improve the quality of their sleep.