The event which marked the start of the band’s sold-out, 82-date world tour, was livestreamed on Netflix to more than 190 countries, including South Korea.
Only around 22,000 people who secured free tickets were allowed into the main concert venue, while other spectators watched the performance on a dozen screens installed along nearby streets.
The concert saw the government implement strict crowd control measures, deploying about 7,000 police officers, including SWAT units equipped with anti-drone systems.
The broadcast topped Netflix’s rankings in 24 countries, the company said.
The show is one of Netflix’s latest moves into live event broadcasting. In 2024, the platform’s broadcast of the boxing match between Mike Tyson and Jake Paul drew more than 108 million viewers globally.
An ascent by American climber Alex Honnald up a Taiwan skyscraper earlier this year was also streamed live on Netflix, with a reported 6.2 million people tuning in.
Meanwhile, BTS and their record label BigHit and Hybe are expected to generate more than $1bn (£740m) from their reunion, driven by concerts, merchandise, licensing, album sales and streaming revenue, according to Billboard.
BTS is Hybe’s main source of income, with the firm’s operating profit slumping during the band’s extended hiatus.