Not held in other editions
| Event type

4 x 100 metres Medley Relay, Mixed

Date29 – 31 July 2021
LocationOlympic Aquatics Centre, 2-1, 2chome, Tatsumi, Koto-ku, Tatsumi-no-Mori Seaside Park, Tokyo, Japan
Participants76 from 16 countries

This was a new event on the Olympic Program and was very hard to predict as nobody knew exactly who would swim for the various nations, and the swim order of men and woman also made prognostication difficult. It had been contested at the World Championships since 2015, with Great Britain winning in 2015, the United States in 2017, and Australia in 2019. All three top swimming nations, they were expected to battle for medals here, alongside China.

The heats were led by Great Britain and China, with the United States and Australia second in heats one and two, respectively. For the final, Britain swam F/M/M/F, with Australia using the same order, while the United States swan M/F/F/M and China used M/M/F/F.

Ryan Murphy opened the backstroke leg for the USA and gave the Americans the early lead, although Italy’s Thomas Ceccon was tied with him at the end of the opening 100. Nicolo Martinenghi put Italy in the lead at 200 with a strong breaststroke leg, as the USA dropped back to sixth, and China second and the Russian Olympic Committee team, which opened with two men, third.

James Guy swam the butterfly leg for Great Britain and put them in front, with China moving into second, as Zhang Yufei swam a strong female butterfly leg, and Italy held on to third. On the freestyle leg, Caeleb Dressel was the only male swimmer but he was too far behind to get into the medals. Great Britain held on the for the gold behind Anna Hopkin while China edged out Australia for the silver medal. The USA finished fifth, only the second time in Olympic history that they had failed to medal in an Olympic swim relay, after the men’s 4 x 200 free relay earlier in Tokyo.

PosLaneSwimmerNOCTimeExchange (Pos)
1Great BritainGBRGold
Kathleen Dawson– (–)
Adam Peaty– (–)
James Guy– (–)
Anna Hopkin– (–)
Freya Anderson– (–)
2People's Republic of ChinaCHNSilver
Xu Jiayu– (–)
Yan Zibei– (–)
Zhang Yufei– (–)
Yang Junxuan– (–)
Kaylee McKeown– (–)
Zac Stubblety-Cook– (–)
Matthew Temple– (–)
Emma McKeon– (–)
Isaac Cooper– (–)
Brianna Throssell– (–)
Bronte Campbell– (–)
Thomas Ceccon– (–)
Nicolò Martinenghi– (–)
Elena Di Liddo– (–)
Federica Pellegrini– (–)
Simone Sabbioni– (–)
5United StatesUSA
Ryan Murphy– (–)
Lydia Jacoby– (–)
Torri Huske– (–)
Caeleb Dressel– (–)
Regan Smith– (–)
Andrew Wilson– (–)
Tom Shields– (–)
Abbey Weitzeil– (–)
Kira Toussaint– (–)
Arno Kamminga– (–)
Nyls Korstanje– (–)
Femke Heemskerk– (–)
Ranomi Kromowidjojo– (–)
7Russian Olympic CommitteeROC
Yevgeny Rylov– (–)
Kirill Prigoda– (–)
Svetlana Chimrova– (–)
Mariya Kameneva– (–)
Grigory Tarasevich– (–)
Arina Surkova– (–)
Anastasia Gorbenko– (–)
Itay Goldfaden– (–)
Gal Cohen Groumi– (–)
Andi Murez– (–)
Anna Konishi– (–)
Shoma Sato– (–)
Katsuhiro Matsumoto– (–)
Rikako Ikee– (–)
Marek Ulrich– (–)
Fabian Schwingenschlögl– (–)
Lisa Höpink– (–)
Annika Bruhn– (–)
Apostolos Khristou– (–)
Konstadinos Meretsolias– (–)
Anna Ntountounaki– (–)
Nora Drakou– (–)
Mikita Tsmyh– (–)
Illia Shymanovich– (–)
Anastasiya Kuliashova– (–)
Nastassia Shkurdai– (–)
Javier Acevedo– (–)
Gabe Mastromatteo– (–)
Katerine Savard– (–)
Rebecca Smith– (–)
Guilherme Basseto– (–)
Felipe Lima– (–)
Giovanna Diamante– (–)
Stephanie Balduccini– (–)
Benedek Kovacs– (–)
Petra Halmai– (–)
Richárd Márton– (–)
Fanni Gyurinovics– (–)
Paulina Peda– (–)
Jan Kozakiewicz– (–)
Jakub Majerski– (–)
Kornelia Fiedkiewicz– (–)