Coupang, the country's largest online retail platform, signalled in a statement that it would challenge the fine in court.
The government's move caps a months-long probe into Coupang, which is incorporated in the United States.
Allegations of a massive data leak first surfaced in November and have become an unexpected source of friction between Seoul and Washington.
The logo of South Korean online delivery service Coupang at the headquarters of Coupang in Seoul, South Korea, on Dec. 9, 2025. Photo by AFP
Seoul's Personal Information Protection Commission said it would "impose a total of 624.68 billion won in fines... on Coupang for violating safety obligations and collecting personal data without legal grounds."
