Swimming at the 2020 Summer Olympics – Men's 4 × 100 metre freestyle relay

The men's 4 × 100 metre freestyle relay event at the 2020 Summer Olympics was held on 25 and 26 July 2021 at the Tokyo Aquatics Centre. It was the thirteenth appearance of the event, which has been held from 1964 to 1972 and then at every Games since 1984.

Summary
The U.S. men defended their title from Rio five years earlier, producing the fastest swim in 13 years. Caeleb Dressel (47.26) gave the U.S. an early lead which Blake Pieroni (47.58) and Bowe Becker (47.44) would maintain over the next 200 m. With Italy two-tenths off a second back after the final changeover, Zach Apple had a sterling anchor leg of 46.69 to separate the U.S. from the field and touch first in 3:08.97.

Meanwhile Italy's Alessandro Miressi (47.72), Thomas Ceccon (47.45) and Lorenzo Zazzeri (47.31) moved from fourth to second before handing over to Manuel Frigo (47.63) who ensured the Italians their first-ever medal in the event, winning silver in a national record of 3:10.11. Australia's Matthew Temple (48.07), Zac Incerti (47.55) and Alexander Graham (48.16), struggled to chase against the rest of the teams throughout the race, until anchor Kyle Chalmers launched a late attack on the home stretch with a 46.44 split - the fastest in the field - to deliver the Australian quartet their second-straight bronze medal in 3:10.22. Swimming in lane 1, Canada were surprisingly in podium contention after receiving strong splits from Brent Hayden (47.99), Joshua Liendo (47.51) and Yuri Kisil (47.15). While Markus Thormeyer (48.17) could not hold off Chalmers's powerful finish, the Canadians shattered their national record to place fourth in 3:10.82.

Hungary's Kristóf Milák (48.24), Szebasztián Szabó (47.44), Richárd Bohus (47.81) and Nándor Németh (47.57) improved throughout the race to come fifth in a national record of 3:11.06. While France received a strong start from Maxime Grousset (47.52) - only 0.26 off the U.S.' Dressel - Florent Manaudou (47.62), Clément Mignon (48.01) and Mehdy Metella (47.94) could not maintain the pace, coming sixth in 3:11.09. While Andrei Minakov (47.71) kept ROC in third at the 100 m mark, the pre-race favourites struggled to mount a challenge against the field and fell to seventh in 3:12.20. Brazil (3:13.41) rounded out the championship field.

Records
Prior to this competition, the existing world and Olympic records were as follows.

No new records were set during the competition.

Qualification
The top 12 teams in this event at the 2019 World Aquatics Championships qualified for the Olympics. An additional 4 teams will qualify through having the fastest times at approved qualifying events during the qualifying period (1 March 2019 to 30 May 2020).

Competition format
The competition consists of two rounds: heats and a final. The relay teams with the best 8 times in the heats advance to the final. Swim-offs are used as necessary to break ties for advancement to the next round.

Schedule
All times are Japan Standard Time (UTC+9)

Heats
The relay teams with the top 8 times, regardless of heat, advanced to the final.