Mollie O'Callaghan

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 previously held the world record in the women's individual 200m freestyle.

Previously, O'Callaghan won two gold and one bronze medallist in the 2020 Summer Olympics as a heats swimmer in relay events.

2020 Tokyo Olympics
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. 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.

2023 World Aquatics Championships
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 × 100 m freestyle relay; the women's 4 × 200 m freestyle relay; and the mixed 4 × 100 m freestyle relay.

Long course metres
split 52.03 (4th leg); with Jack Cartwright (1st leg), Kyle Chalmers (2nd leg), Madison Wilson (3rd leg)

split 1:54.80 (3rd leg); with Madison Wilson (1st leg), Kiah Melverton (2nd leg), Ariarne Titmus (4th leg)

split 52.08 (1st leg); with Shayna Jack (2nd leg), Meg Harris (3rd leg), Emma McKeon (4th leg)

split 1:53.66 (1st leg); with Shayna Jack (2nd leg), Brianna Throssell (3rd leg), Ariarne Titmus (4th leg)

split 51.71 (4th leg); with Jack Cartwright (1st leg), Kyle Chalmers (2nd leg), Shayna Jack (3rd leg)

Short course metres
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)

Honours

 * In the 2022 Australia Day Honours, O'Callaghan was awarded the Medal of the Order of Australia.
 * Swimming Australia, Olympic Program Swimmer of the Year: 2022 and 2023
 * Australian Institute of Sport Performance Awards Performance of the Year 2023