The women's 100 metre freestyle event at the 2020 Summer Olympics was held from 28 to 30 July 2021 at the Tokyo Aquatics Centre. It was the event's twenty-fifth consecutive appearance, having been held at every edition since 1912.
The medals for the competition were presented by Gunilla Lindberg, Sweden; IOC Member, and the medalists' bouquets were presented by Dr. Julio Maglione, Uruguay; FINA Immediate Past President.
Records
Prior to this competition, the existing world and Olympic records were as follows.
The following records were established during the competition:
Qualification
The Olympic Qualifying Time for the event is 54.38 seconds. 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 56.01 seconds. 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 female 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 8 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)
Results
Heats
The swimmers with the top 16 times, regardless of heat, advanced to the semifinals.
Swim-off
Semifinals
The swimmers with the best 8 times, regardless of heat, advanced to the final.