Objectives: This study examined the effects of the interaction between exercise and sleep on frailty severity in community-dwelling older adults.Materials and Methods: This was a cross-sectional study. Data were collected in July 2019. In total, 2021 adults participated who responded to a questionnaire. Among them, 672 participants (317 men and 355 women) with valid responses were included in the analysis. Ordinal logistic regression analysis was performed to examine the association between frailty severity and the interaction between exercise and sleep. The dependent variable represents three different levels of frailty. The independent variables included basic information and interaction between exercise and sleep.Results: The results of ordinal logistic regression analysis (odds ratio [OR]) showed that the period from the start of exercise (OR=0.96), age (OR=1.00 for participants in their 60 s, OR=1.65 for those in their 70s, and OR=3.13 for those aged >80 years), poor subjective health perception (OR=2.12), poor quality of sleep (OR=1.88), stress (OR=1.62), and exercise–sleep interaction (OR=1.00 based on good-exercise–good-sleep interaction, OR=3.09 poor-exercise–good-sleep interaction, and OR=3.50 poor-exercise–poor-sleep interaction) significantly contributed to the model. The Nagelkerke coefficient of determination adjusted for degrees-of-freedom (R2), which represents the contribution rate of the regression equation, was 0.334.Conclusions: Our results suggest that a combination of good exercise and good sleep is needed to prevent frailty progression in community-dwelling older adults.