Objective: We aimed to determine whether the association of sleep status with frailty differs between age groups of older adults. Method: This cross-sectional study was part of the observational Septuagenarians, Octogenarians, Nonagenarians Investigation with Centenarians (SONIC) study. Subjects were community-dwelling older adults in their 70s and 80s. Frailty was evaluated using the Japanese version of the Cardiovascular Health Study criteria (J-CHS). Pittsburgh Sleep Quality Index (PSQI) was used to assess sleep status. Poor sleep quality was defined as a PSQI global score ≥6. Sleep duration was categorized as short (<6 hr), normal (6-8), and long (>8). We performed multivariable logistic regression to investigate the association between sleep status and frailty separately for each age group adjusted for multiple covariates. Results: In those in their 70s, long sleep duration and sleep medication use were independently associated with frailty. In those in their 80s, poor sleep quality was independently associated with frailty. Conclusions: The association between sleep status and frailty was different between age groups. The findings underscore the importance of incorporating the evaluation of sleep quantity and non-pharmacological therapies in those in their 70s and the evaluation of sleep quality in those in their 80s to help prevent the onset of frailty.