Abstract Background The present study investigated whether the frequency of sleep medication use affects subjective cognitive decline (SCD) or SCD with functional difficulties in elderly individuals. Methods The 2018 Korea Community Health Survey data, which consists of national representative and community-based data, was used in this study. A total of 57,050 individuals aged 65 years or older were included in this study. SCD was measured using the Behavioral Risk Factor Surveillance System. A logistic regression analysis was used to analyze the data. Results In total, 16,966 (29.7%) participants had SCD and 3,487 (6.1%) had SCD with functional difficulties. The elderly individuals who took sleep medication more than once a week had higher risks of both SCD and SCD with functional difficulties than those who did not take any sleep medication in a month (SCD: odds ratio [OR] = 1.329, 95% confidence interval [CI] = 1.194–1.480; SCD with functional difficulties: OR = 1.752, 95% CI = 1.491–2.058). Conclusions Frequent sleep medication use was associated with both SCD and SCD with functional difficulties. This study suggests that early detection of cognitive impairment and efforts to reduce the frequent use of sleeping pills in patients with insomnia might be helpful to reduce the burden of SCD and SCD with functional difficulties in the elderly population.