Swimming at the 2020 Summer Olympics – Women's 100 metre freestyle

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.

Summary
Australia's Emma McKeon became only the second woman to break the 52 second threshold in the event, setting a new Olympic and Oceanian record of 51.96. With the victory, McKeon won her first individual Olympic title and Australia's first in the event since Jodie Henry in 2004.

Though first at the 50, Hong Kong's Siobhan Haughey was overtaken by McKeon down the stretch but still won her second silver medal at these Games with an Asian record of 52.27. Australia's Cate Campbell, the resounding favourite for gold in 2016, had a comeback performance to take the bronze medal in 52.52. By joining teammate McKeon on the podium, the pair's 1-3 finish marked the first time two Australians placed on the podium in this event since the country's medal sweep in Melbourne 1956.

One of two defending champions Penny Oleksiak of Canada finished narrowly behind Campbell in a Canadian record of 52.57. Sweden's world-record holder and 2016 bronze medallist Sarah Sjöström was last at the 50 but managed to touch in 52.68 for fifth. Femke Heemskerk (52.79) clocked a new Dutch record to come sixth while Great Britain's Anna Hopkin (52.83) and the U.S.'s Abbey Weitzeil (53.23) rounded out the finalists.

The medals for the competition were presented by Sweden's Gunilla Lindberg, IOC member, and the gifts were presented by Uruguay's Julio Maglione, former FINA President.

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

The following records were established during the competition:

* Olympic record split from the 4 × 100 m freestyle relay

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)

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.