South Korea's 5G users stood at 11.85 million as of end-December last year, up over 900,000 from the previous month, according to the data from the Ministry of Science and ICT.
The figure accounted for 16.8 per cent of the total 70.5 million mobile network subscriptions in the country.
The number of 5G users picked up in the second half of last year, thanks to launches of new 5G phones, including Apple Inc.'s iPhone 12 series and Samsung Electronics' Galaxy Note 20 models.
The country's migration to the high-speed network is expected to accelerate further with the launches of Samsung's new flagship Galaxy S21 models and cheaper data plans from mobile carriers sold through online retail channels, reports Yonhap news agency.
With the growing number of 5G users, local mobile carriers are focusing on adopting new technology, such as standalone 5G, to improve network quality.
South Korean telecom operators currently support non-standalone 5G, which requires support from the previous 4G LTE network.
Users on the 4G network accounted for the majority of mobile subscriptions last year at 52.5 million, or 74.5 per cent of the total.