Thailand ranked second with 1.85 million arrivals, followed by the Philippines with 1.57 million, according to data from tourism ministries across the region.
Singapore came in fourth with 594,000 South Korean arrivals, while Malaysia recorded 475,000.
Industry insiders attributed the surge in South Korean travelers to Vietnam to its affordability, cooler climate, favorable visa policies, and growing popularity.
South Korean tourists can stay in Vietnam for a maximum of 45 days without a visa.
The increase in direct flights between South Korea and Vietnam, coupled with tourism campaigns on Korean media, also contributed to the steady rise in visitor numbers.
Vietnam and the Philippines remained the top international travel destinations for South Korean families with children under 10 for the second consecutive year, according to Hana Tour, South Korea's largest travel agency.
Based on booking trends in January and international travel demand during the winter holiday, Vietnam accounted for 26.6% of all overseas family bookings, making it the most preferred destination.
In Southeast Asia, South Koreans were the largest source of inbound tourists to both Vietnam and the Philippines in 2024.