The men's welterweight boxing event at the 2020 Summer Olympics took place between 24 July and 3 August 2021 at the Ryōgoku Kokugikan.

Three-time Olympian, 2012 bronze medalist and reigning World Champion Andrey Zamkovoy of Russia has qualified for the Games.

The 2016 Olympic champion, Daniyar Yeleussinov of Kazakhstan, turned professional and did not attempt to qualify.

A National Olympic Committee (NOC) could enter only 1 qualified boxer in the weight class.

Judges consider "number of blows landed on the target areas, domination of the bout, technique and tactical superiority and competitiveness."