Kingdom: Legendary War (Korean: 킹덤: 레전더리 워) is a television program that aired on Mnet beginning on April 1, 2021, and ending on June 3, 2021.

During the finale on June 3, 2021, Stray Kids won the program, finishing in 1st place.

The first parts involves the six individual groups being sorted into two larger teams (selected by Ateez, the highest scoring team in the previous round in terms of the total points in experts' votes plus self-evaluation).

The six boy groups will each perform a newly produced song live on the final episode.

On March 29, 2021, controversy arose following the reports from industry representatives of an issue in the midst of recording performances during round one.

Each group were notified the maximum budget for stage decoration would be ₩5 million won (approximately $4,416) per team.

However, during the recording, agencies from groups who comparatively did not have an extravagant set and props that appeared to be far over the budget reportedly confronted the production team on the matter and questioned if it was due to CJ ENM investing in the other group's agency.

[28] In response, during the press conference held on April 1, CP Park Chan-wook stated: "I apologize that an issue was raised ahead of the show's premiere.

The information below is detailed according to the songwriting credits available on the respective full performance videos uploaded on Mnet's official YouTube channel.