Background: In South Korea, many individuals were self-quarantined for the coronavirus disease 2019 (COVID-19) after the quarantine criteria were extended to all overseas travelers. This study was conducted to identify the non-compliance rate of self-quarantine for COVID-19 cases and assess the impact of a one-strike out policy and an increased amount of penalty for the violating self-quarantine in South Korea. Methods: The self-quarantine non-compliance rate for COVID-19 was examined using publicly available data. We collected the daily number of quarantine and quarantine violation cases from March 22 to June 10, 2020. A Poisson regression analysis was conducted to identify the impact of additional sanctions for the quarantine violation. Results: The median number of individuals quarantined per day was 36,561 (interquartile range of 34,408–41,961). The median number of daily self-quarantine violations was six (range of 0–13). The median rate of self-quarantine violations was 1.6 per 10,000 self-quarantined individuals (range 0.0–8.0 per 10,000 self-quarantined individuals). The additional sanction has no significant impact on the number of violations among quarantine individuals (p=0.99). Conclusions: The additional sanction for the violation of quarantined individuals did not reduce the self-quarantine violations. Further studies are warranted to strengthen the compliance of self-quarantine for future pandemics.