Returning from their triumph five years earlier in Rio, the experienced trio of
Emma McKeon and sisters
Bronte and
Cate Campbell joined with the youngster
Meg Harris to win Australia's third consecutive Olympic title in dominating fashion. Bronte led off the quartet in 53.01 before handing over to Harris (53.09). Holding a marginal gap over the field, McKeon blasted a 51.35 split - the quickest in the field and fifth-fastest of all time - to give the Australians a monstrous lead of over two seconds. As she did in Rio, Cate (52.24) anchored Australia home to win gold in a world record of 3:29.69. Moreover, the Australians' victory margin of 3.09 seconds was the largest in the event since the U.S. won by 3.22 seconds in 2000. Canada's
Kayla Sanchez (53.42) and
Maggie Mac Neil (53.47) handed the third-leg duties to
Rebecca Smith (53.63), who moved the Canadians from fifth to fourth but still 0.67 seconds behind the pace of the Americans. However, in a thrilling duel between the 100 m freestyle defending champions
Penny Oleksiak and
Simone Manuel, Canada's Oleksiak split 52.26 to overtake the U.S.' Manuel (52.96) and secure Canada a surprise silver medal in 3:32.78 - their best finish in the event after three previous bronze-medal feats (1968, 1976, 2016). While
Erika Brown's 54.02 lead-off had the U.S. in sixth, the remaining legs from
Abbey Weitzeil (52.68),
Natalie Hinds (53.15) and Manuel helped the U.S. to recover and win bronze in 3:32.81, just 0.03 seconds behind Canada. Winners in 2008, the Netherlands (3:33.70) fell short of the podium to come fourth despite valiant efforts from the 2012 100 m freestyle champion
Ranomi Kromowidjojo (52.87) and
Femke Heemskerk (52.05), who had the second fastest split in the field behind McKeon. Great Britain (3:33.96) edged out Sweden (3:34.69), who were led off in an Olympic record of 52.69 by superstar
Sarah Sjöström, for fifth place. China (3:34.76) and Denmark (3:35.70) rounded out the championship field. ==Records==