The country recorded 7,630 new cases on Saturday, the Korea Disease Control and Prevention Agency (KDCA) said, above the 7,009 cases reported a day earlier and near the mid-December record of 7,848 logged.
South Korea in mid-January extended tougher social distancing rules for three weeks, including a 9 p.m. curfew for restaurants, cafes and bars, and limits on private gatherings, ahead of the holiday that starts on Saturday.
Tens of millions of Koreans across the country typically travel during Lunar New Year for family gatherings during one of the country's main holidays.
South Korea has recorded 733,902 COVID-19 infections and 6,540 deaths, KDCA data showed, although nearly 95% of adults have been fully vaccinated and more than half having received a booster shot.
To contain the rapid spread of the virus, health officials have required proof of vaccination and a booster to gain access to most public facilities, but a court ruled that large shops and teenagers should be temporarily excluded from COVID-19 vaccine pass mandates.
(Reporting by Joori Roh; Editing by WIlliam Mallard)