The 2021 Southeast Asian Games, officially known as the 31st Southeast Asian Games, 31st SEA Games or SEA Games 31, and also recognized as Viet Nam 2021, was the 31st edition of the Southeast Asian Games, the biennial regional multi-sport event which was held in Hanoi, Vietnam and its surrounding cities from 12 to 23 May 2022.

SEA Games, officially known as the South East Asian Games, is a biennial multi-sport event involving participants from the current 11 countries of Southeast Asia. The games are under the regulation of the Southeast Asian Games Federation with supervision by the International Olympic Committee (IOC) and the Olympic Council of Asia (OCA). The SEA Games is one of the five subregional Games of the Olympic Council of Asia (OCA).