Curbs will return from Saturday to Jan. 2, limiting gatherings to no more than four people - as long as they are vaccinated - and forcing restaurants, cafes and nightly entertainment facilities to close by 9 p.m. and movie theatres and internet cafes by 10 p.m., Prime Minister Kim Boo-kyum said.
Unvaccinated people can only dine out alone, or use takeout or delivery services.
The measures came a day after South Korea posted another new record daily coronavirus tally amid a persistent spike in breakthrough infections among those vaccinated and serious cases.
More than 94% of South Korean adults are fully vaccinated, but the number of new cases has surged nearly five-fold and the number of serious cases tripled since the rules were eased last month, adding to strains on the country's medical system.