split 51.71 (4th leg); with Jack Cartwright (1st leg), Kyle Chalmers (2nd leg), Shayna Jack (3rd leg)
1952
split 52.03 (4th leg); with Jack Cartwright (1st leg), Kyle Chalmers (2nd leg), Madison Wilson (3rd leg)
split 52.08 (1st leg); with Shayna Jack (2nd leg), Meg Harris (3rd leg), Emma McKeon (4th leg)
split 52.19 (1st leg); with Madison Wilson (2nd leg), Meg Harris (3rd leg), Emma McKeon (4th leg)
split 1:52.83 (2nd leg), with Madison Wilson (1st leg), Leah Neale (3rd leg), Lani Pallister (4th leg)
split 25.49 (backstroke leg); with Chelsea Hodges (breaststroke leg), Emma McKeon (butterfly leg), Madison Wilson (freestyle leg)
1953
split 1:53.66 (1st leg); with Shayna Jack (2nd leg), Brianna Throssell (3rd leg), Ariarne Titmus (4th leg)
1954
split 1:54.80 (3rd leg); with Madison Wilson (1st leg), Kiah Melverton (2nd leg), Ariarne Titmus (4th leg)
2004
Mollie Grace O'Callaghan, (born 2 April 2004) is an Australian swimmer.
She was the 2023 world champion in the women's 100m and 200m freestyle individual events, and part of the world champion 4 × 100 m and 4 × 200 m Australian women's relay teams together with 4 × 100 m mixed relay team.
she is the world record holder in the women's individual 200m freestyle.
2010
Swimming the 1st leg for Australia in the heats of the 4 × 100 metre freestyle relay, she posted a time of 53.08 and received a gold medal after the Australian team won the final.
In the 4 × 200 metre freestyle relay preliminaries, O'Callaghan swam a junior world record of 1:55.11 when swimming the lead off leg.
Her time would have placed her fifth in the
200 metre freestyle final.
However, because the Australian coaches had previously decided to use four fresh swimmers in the final, O'Callaghan was controversially not selected for the final where Australia finished third.
In a heat of the 4 × 100 metre medley relay, O'Callaghan again posted
a competitive time; her anchor leg split was 52.35, only 0.24 seconds slower than the fastest freestyle split in the final by Cate Campbell.
At the 2023 World Aquatics Championships, O'Callaghan was a world champion in five events.
O'Callaghan won the women's 100m freestyle in 52.16, after qualifying in second place, and the women's 200m freestyle in a world record time of 1:52.85 after qualifying in third place.
She was the first woman to win both of these events in a single world championship.
O'Callaghan was also part of three champion relay teams, each of which set a world-record time: the women's 4×100m freestyle relay; the women's 4×200m freestyle relay; and the mixed 4×100m freestyle relay.
2020
Previously, O'Callaghan won two gold and one bronze medallist in the 2020 Summer Olympics as a heats swimmer in relay events.
O'Callaghan swam for the Australian team in the preliminaries of all three women's relays at the 2020 Summer Olympics in Tokyo, receiving two gold medals and one bronze for her contribution.
