The 2021–22 season is Bangkok United Football Club's 13th in the new era since they took over from Bangkok University Football Club in 2009.

In the league, the season was supposed to start on 31 July 2021 and concluded on 21 May 2022.

[1] Then, due to the situation of the COVID-19 pandemic is still severe, FA Thailand decided to postpone the season to start on 13 August 2021 instead.

[2][3] However, as it stands on 23 July 2021, the COVID-19's situation is getting even worse.

Therefore, FA Thailand decided to postpone the opening day for the second time to start on 3 September 2021.