As of 2023, the most popular YouTube channels in South Korea are predominantly dominated by K-Pop and entertainment-related content. Here's a breakdown of some of the top channels based on various sources:

1. BLACKPINK: With over 84.7 million subscribers, BLACKPINK's official YouTube channel is not only the most subscribed in South Korea but also ranks highly globally. Their channel features music videos, behind-the-scenes content, and other exclusive material related to the girl group​​​​.
2. BANGTANTV: This is the official channel of BTS, one of the world's most popular boy bands. With approximately 73.9 million subscribers, it ranks as the second most subscribed channel in South Korea. The channel includes music videos, behind-the-scenes footage, and other promotional materials related to the group​​​​.
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4. HYBE LABELS: Home to BTS, SEVENTEEN, and other K-Pop artists, this channel has about 69.5 million subscribers. It serves as a hub for music videos and content from artists under the HYBE Labels umbrella​​​​.
5. SMTOWN: The official channel for SM Entertainment, featuring artists like EXO, Red Velvet, NCT, and aespa, has around 31.5 million subscribers. It offers a range of content including music videos and artist-focused material​​​​.
6. JYP Entertainment: The official channel of JYP Entertainment, home to groups like TWICE and Stray Kids, has approximately 26.6 million subscribers. It provides music videos and other content related to its artists​​​​.
7. 1MILLION Dance Studio: This dance academy and K-Pop choreography label have about 25.9 million subscribers. It showcases various dance performances and tutorials​​​​.
8. 1theK (원더케이): Managed by Kakao Entertainment, this channel, with about 24.4 million subscribers, produces a wide array of K-Pop-related content, including music videos and artist promotions​​​​.
9. Mnet K-POP: This is the official YouTube channel for Mnet, a South Korean music channel. It has around 20.3 million subscribers and features a variety of music-related content, including performances and music show clips​​​​.
10. KBS WORLD TV: The official channel for the Korean Broadcasting System, it provides a variety of content including K-Dramas, news, and entertainment shows, with around 18.7 million subscribers​​​​.
11. officialpsy: Psy, famous for his hit song "Gangnam Style," has an official channel with about 17.9 million subscribers, showcasing his music videos and other personal content​​​​.

These channels highlight the global popularity of K-Pop and the diverse entertainment content that South Korea offers, reflecting a mix of music, dance, and cultural programming that appeals to a wide audience both domestically and internationally.