|Date||24 – 25 July 2021|
|Location||Olympic Aquatics Centre, 2-1, 2chome, Tatsumi, Koto-ku, Tatsumi-no-Mori Seaside Park, Tokyo, Japan|
|Participants||17 from 13 countries|
Hungary’s Katinka Hosszú had dominated this event since 2016, winning every major international title. However, she did not have any of the top times in 2021, was now 32-years-old, and had recently split with her husband and coach, Shane Tusup. The leaders of the year list were the Americans from the US Olympic Trials, Emma Weyant and Hali Flickinger. Japan’s Yui Ohashi was the silver medalist behind Hosszú at the 2018 World Championships and was expected to contend for a medal.
With the late withdrawal of Canadian Sydney Pickrem, only 17 swimmers started the preliminary round, which was led by Weyant in 4:33.55, almost two seconds ahead of Great Britain’s Aimee Willmott, with Ohashi third and Hosszú qualifying only seventh.
In the final Hosszú had the early lead on the backstroke leg but was soon overtaken by Flickinger and Ohashi. Ohashi took the lead for good on the breaststroke portion of the race, followed by Weyant, and they would hold on to finish 1-2, as Flickinger came in third, two seconds back of Weyant.
Hosszú trailed in fifth and that would be her best finish in any event in Tokyo. Ohashi would return in a few days to win the IM double by taking the 200 IM. Flickinger would later add another bronze medal in the 200 butterfly.