The men's tournament of water polo at the 2020 Summer Olympics at Tokyo, Japan began on 25 July and ended on 8 August 2021.

It was held at the Tokyo Tatsumi International Swimming Center.

[4] The medals for the competition were presented by Nenad Lalović, IOC Executive Board Member; Serbia and the medalists' bouquets were presented by Andrey Kryukov, Kazakhstan; FINA Bureau Member.

The competition began on 25 July, and matches were held every other day.

At each match time, two matches were played simultaneously (one from each group during preliminary round, two quarterfinals during that round, one main semifinal and one classification 5 to 8 semifinal during the semifinal round, and the two classification games on the final day) except for the bronze and gold medal matches.