It is hard to determine who had the largest concert in Korea prior to 2018 or 19, since reliable figures do not exist.
On 2016 Big Bang had a one day concert at the Soccer Stadium.
YG claimed an audience of 70,000 but more reliable figures say it was 65,000. However, some ticets were free tickets, and it is impossible to determine how many of them attended it for free.
On 2017
(All figures from the Olympic Stadium except for 2023 and 24)
Exo - claims to be 70,000, actually probably around 60,000
H.O.T Reunion -
It claimed to have 100,000 attendees, but given that its next concert was held at the Gochuck, for about 45,000 total, the real number was significantly short of what was claimed. How much, who knows, but probably a bit north of 80,000.
2018
BTS - claimed to be 90,000. Actually probably around 85,000
2019
BTS - 129,268, 3 day event. About 43,000/day.
Probably the first reliable number in the concert history of Korea.
However, amazingly, no KPop idols planned to match it
2020
BTS planned a 4 day event at Seoul, which would have had 172,000 given the capacity of the previous tour.
However, amazingly, no KPop acts tried to rival BTS.
Instead, a nonKPop act decided to have a 2 day concert.
The Owner of Edam Entertainment, and the Ultimate Nemesis of BTS, planned to have a 2 Day event in a stadium, which would have had about 80,000
But both BTS and its nemesis didn't get to hold their concerts because of heavy Covid restrictions, which led to no concerts in 2020
2022
BTS had its 1/3 capacity concert on March. Reliable numbers are not available, but it is estimated that 45,000 attended it.
At that time the city of Pusan was trying to hold a world expo , competing with Saudi Arabia's Riyadh. So a free concert was announced in a spot, in the middle of nowhere, for 100,000.
That would have been the largest one day event, ever, in the history of Korea.
However, that spot had no amenities and was hard to get to, so some people began to cry that it was not safe.
Meanwhile, BTS' nemesis, who had lost the control of Edam Entertainment back to Kakao, but the desire to end KPop not having diminished at all, decided to steal the luster by deciding to hold a concert in Sep.
In the end, BTS' free concert was attended by 50,000 , which is the capacity of the decrepit stadium in Pusan, while BTS' nemisis' concert as attended by 89,000, ending with a huge victory by BTS' nemesis.
NCT 127 and NCT Dream had concerts at stadiums but about 50,000 each.
Psy also had a 3 day concert but attended by about 75,000 total.
So, after 2020, BTS' nemesis had the largest concert in Korea.
2023
BlackPink had a concert at the Gochuck for 35,000, the largest concert done by a KPop female act in Korean history, since BTS' nemesis is NOT a Kpop figure
Seventeen had a concert at the Gochuck for 37,000, largest in 2023
2024
Seventeen had a 2 day concert at the Incheon stadium for about 56,000
Seventeen had a 2 day concert at the Soccer stadium for about 70,000
Lim Youngwoong, a trottist, had a 2 day concert at the Soccer Stadium for about 90,000, beating the record of BTS' nemesis for the largest concert to be held in Korea after the Covid era
Unfortunately, that led to BTS' nemesis to up the ante, and she will have 108,000 attendees
So, from 2017, the largest concerts to be held in Korea are
BTS - 2019
(BTS' nemesis - 2024)
Lim Youngwoong - 2024
BTS - 2018
BTS' nemesis - 2022
H.O.T - 2017
Seventeen - 2024
and so on.
It seems BTS' nemesis is trying to have a larger concert in Korea than BTS, to show who is the boss in Korea at least.