Swimming at the 2020 Summer Olympics – Women's 100 metre butterfly#Heats

{{Cleanup section|reason=This section is editorialised. It uses peacock terms which are not in-keeping with a neutral, encyclopedic tone.|date=April 2025}}Canada's defending World champion Maggie Mac Neil pulled away from a tight field to win her nation's first Olympic title in the event. Swimming out in lane 7, Mac Neil touched seventh at the 50 m mark but used a blistering underwater off the turn to catapult herself near the front and win gold in an Americas record of 55.59. China's Zhang Yufei, who was the fastest qualifier through the heats and semi-finals, was first at the turn. However, she could not withstand MacNeil's fast finish and settled for silver 5 hundredths of a second back in 55.64.

Australia's Emma McKeon reset her Oceanian record from the heats to win bronze in 55.72, edging out the U.S.' Torri Huske (55.73) by one hundredth of a second. Huske, one of the pre-Olympics favourites, could not replicate her stunning American record of 55.66 and took fourth. Sweden's Louise Hansson set a personal best time of 56.22 to place fifth. Third at the 50 m mark, France's Marie Wattel was a shade off her national record from the semi-finals, clocking 56.27 to come sixth.

Sweden's defending champion Sarah Sjöström, coming off elbow surgery in February, produced a valiant effort to place seventh in 56.91 - her slowest time throughout the rounds. Belarus' Anastasiya Shkurdai (57.05) rounded out the championship field.

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

{{World Olympic Record

| world_athlete = {{flagathlete|Sarah Sjöström |SWE}}

| world_mark = 55.48

| world_place = Rio de Janeiro, Brazil

| world_date = 7 August 2016

| world_ref = {{cite news|title=Swimming: Sjostrom avoids 'disasters' to win 100m butterfly|url=https://www.reuters.com/article/us-olympics-rio-swimming-w-100mbutterfly-idUSKCN10J038|publisher=Reuters |date=7 August 2016|accessdate=27 August 2016}}

| olympic_athlete = {{flagIOCathlete|Sarah Sjöström |SWE|2016 Summer}}

| olympic_mark = 55.48

| olympic_place = Rio de Janeiro, Brazil

| olympic_date = 7 August 2016

| olympic_ref =

}}

No new records were set during the competition.

{{main|Swimming at the 2020 Summer Olympics – Qualification}}

The Olympic Qualifying Time for the event is 57.92 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 59.66 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.{{cite news|title=Tokyo 2020 – FINA Swimming Qualification System|url= https://www.fina.org/sites/default/files/general/final_-_2018-03-19_-_tokyo_2020_-_qualification_system_-_swimming_-_eng.pdf|work=Tokyo 2020 |publisher=FINA |accessdate=29 January 2020}}

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.{{cite web|title=FINA Swimming Rulebook, 2017–21|url=https://www.fina.org/sites/default/files/2017_2021_swimming_12092017_ok_0.pdf|website=FINA|accessdate=29 January 2020}}

All times are Japan Standard Time (UTC+9)

The swimmers with the top 16 times, regardless of heat, advanced to the semifinals.{{Cite web |url=https://olympics.com/tokyo-2020/olympic-games/resOG2020-/pdf/OG2020-/SWM/OG2020-_SWM_C74A_SWMW100MBF------------HEAT--------.pdf |title=Heats results |access-date=24 July 2021 |archive-date=24 July 2021 |archive-url=https://web.archive.org/web/20210724124909/https://olympics.com/tokyo-2020/olympic-games/resOG2020-/pdf/OG2020-/SWM/OG2020-_SWM_C74A_SWMW100MBF------------HEAT--------.pdf |url-status=dead }}

The swimmers with the best 8 times, regardless of heat, advanced to the final.{{Cite web |url=https://olympics.com/tokyo-2020/olympic-games/resOG2020-/pdf/OG2020-/SWM/OG2020-_SWM_C74A_SWMW100MBF------------SFNL--------.pdf |title=Semifinals results |access-date=1 August 2021 |archive-date=23 August 2021 |archive-url=https://web.archive.org/web/20210823113356/https://olympics.com/tokyo-2020/olympic-games/resOG2020-/pdf/OG2020-/SWM/OG2020-_SWM_C74A_SWMW100MBF------------SFNL--------.pdf |url-status=dead }}

{{Cite web |url=https://olympics.com/tokyo-2020/olympic-games/resOG2020-/pdf/OG2020-/SWM/OG2020-_SWM_C73A1_SWMW100MBF------------FNL-000100--.pdf |title=Final results |access-date=1 August 2021 |archive-date=23 August 2021 |archive-url=https://web.archive.org/web/20210823113415/https://olympics.com/tokyo-2020/olympic-games/resOG2020-/pdf/OG2020-/SWM/OG2020-_SWM_C73A1_SWMW100MBF------------FNL-000100--.pdf |url-status=dead }}

{{Reflist}}

{{Footer Olympic Champions 100 m Butterfly Women}}

{{DEFAULTSORT:Swimming at the 2020 Summer Olympics - Women's 100 metre butterfly}}

Women's 00100 metre butterfly

Olympics

Category:Women's events at the 2020 Summer Olympics

Category:2021 in women's swimming