The country reported 2,771 new COVID-19 cases, including 2,735 local infections, bringing the total caseload to 301,172, according to the Korea Disease Control and Prevention Agency (KDCA).
Still, the figure is the second largest since the outbreak of COVID-19 in January last year in the country despite fewer tests over the weekend.
The KDCA reported a fresh high of 3,273 on Saturday, including 3,245 local infections, as millions of South Koreans returned home after Chuseok, the Korean autumn harvest celebration, which ran from Monday to Wednesday.
Saturday's daily caseload jumped 842 from the previous day's record high of 2,431.
Daily cases have stayed over 1,000 for the last 82 days amid the fast spread of the more transmissible delta variant across the country.
The country added nine more deaths from COVID-19, raising the death toll to 2,450.
The greater Seoul area, the hotbed of South Korea's latest wave of the pandemic, has been under Level 4 distancing measures, the highest in the country's four-tier system, since July with most other areas being under Level 3.
Private gatherings are allowed to be a maximum of six on the condition that four of them are fully vaccinated.
Health authorities are weighing whether to further tighten social distancing rules, tracing the recent virus trends.
The Seoul metropolitan area, home to half of the nation's 52 million population, accounted for 72.7 percent of the total infections.
Seoul reported 923 cases and the surrounding Gyeonggi Province 922 cases, with the western port city of Incheon adding 169 cases.
A total of 38 million people, or 74.1 percent of the country's population, have received their first shots of COVID-19 vaccines, and 23.2 million people, or 45.2 percent, have been fully vaccinated, the KDCA said.
Under a goal to achieve herd immunity by November, the government plans to begin administering COVID-19 vaccines to pregnant women, and people aged between 12 and 17 next month.
Imported cases came to 36, including seven from the Philippines.
The number of patients with serious symptoms across the country reached 320, down nine from the previous day.
The total number of people released from quarantine after making full recoveries was 268,140, up 1,726 from a day earlier. (Yonhap)