Swimming at the 2020 Summer Olympics – Men's 200 metre breaststroke

The men's 200 metre breaststroke event at the 2020 Summer Olympics was held from 27 to 29 July 2021 at the Tokyo Aquatics Centre. It was the event's twenty-sixth consecutive appearance, having been held at every edition since 1908.

Summary
Australia's Zac Stubblety-Cook came from behind to become his nation's first Olympic champion in this event since Ian O'Brien in 1964. Almost a body length behind Dutch early leader Arno Kamminga through the first 100 m of the race, Stubblety-Cook moved through the field in the penultimate lap. Still more than a second back at the final turn, Stubblety-Cook powered home to overtake the field and win gold in an Olympic record time of 2:06.38, only 0.1 of a second shy of his personal best time. Meanwhile, Kamminga shot out to an early lead, turning under world record pace at the 50 m mark. One and a quarter of a second ahead of world record pace at the 150 m mark, Kamminga faded over the closing stages of the race to take his second silver at these Games in 2:07.01.

Finland's Matti Mattson lowered his Finnish record by 1.1 seconds to claim a surprise bronze in 2:07.13. ROC's world record holder and defending bronze medallist Anton Chupkov (2:07.24) missed the podium by 11 one-hundredths to place fourth. The U.S.' Nic Fink (2:07.93) could not replicate his trials performance, falling to fifth. Great Britain's James Wilby was in second after the first lap but could not hang on with the leaders, placing sixth in 2:08.19. Japan's Ryuya Mura (2:08.42) and Sweden's Erik Persson (2:08.88) rounded out the field.

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

The following record was established during the competition:

Qualification
The Olympic Qualifying Time for the event is 2:10.35. Up to two swimmers per National Olympic Committee (NOC) can automatically qualify by swimming that time at an approved qualification event. The Olympic Selection Time is 2:14.26. Up to one swimmer per NOC meeting that time is eligible for selection, allocated by world ranking until the maximum quota for all swimming events is reached. NOCs without a male swimmer qualified in any event can also use their universality place.

Competition format
The competition consists of three rounds: heats, semifinals, and a final. The swimmers with the best 16 times in the heats advance to the semifinals. The swimmers with the best eight times in the semifinals 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 swimmers with the top 16 times, regardless of heat, advanced to the semifinals.

Semifinals
The swimmers with the best 8 times, regardless of heat, advanced to the final.