Mollie O’Callaghan is an Olympian and world champion who represents Australia internationally in swimming. She broke Federica Pellegrini’s 14-year-old world record of 1:52.98 in 2023.
Mollie O’Callaghan’s international career began in 2019, when at age 15, she took part in the World Championships in Budapest, Hungary, for the Australian national team.
In Budapest, she won a silver medal in the women’s 400m freestyle relay.
2020 Queensland Short Course Championships
At the 2020 Queensland Short Course Championships, O’Callaghan set the new national 16 years age group record in the 100m freestyle with a time of 52.10. She also dominated the backstroke events, winning gold in 50/100/200m events.
2020 Tokyo Olympics
In Tokyo, O’Callaghan brought home two gold medals and a bronze at 17 years old — the youngest member of the squad — swimming in the heats of the 4×100 free relay (gold), 4×100 medley relay (gold), and 4×200 free relay (bronze).
2022 Australian Championships/Trials
The 2022 Australian Swimming Championship served as a qualifier for the 2022 FINA World Championships and 2022 Commonwealth Games. The 18-year-old rising star qualified to swim a whopping 5 individual events at the Worlds in as many days at the meet.
The performance that stands out above the rest came in the women’s 100 freestyle.
In the women’s 100m freestyle prelims, O’Callaghan became the first woman sub-53 in the 100m free in 2022, clocking 52.83 for a new best time. She had previously been 53.08, done leading off Australia’s 400 free relay in the prelims at the Olympics last summer. In the final, O’Callaghan was faster, setting a new personal best of 52.49.
O’Callaghan went onto qualify for individual swims in the 100 free, 200 free, 50 back, 100 back and 200 back, although she opted out of the individual backstroke races for Budapest to focus on her freestyle swims and Australia relays.
2022 World Championships
Mollie started her packed schedule in Budapest with the 400 free relay, where she led-off in 52.70 to help Australia dominate the heat and take gold. On day 4 in the 200 free, after making it through the prelims and semis, O’Callaghan put it out there in the final, going out strong and nearly holding on until the end, only getting passed by China’s Yang Junxuan to earn silver medal.
On night 5, O’Callaghan moved through to the final of the 100 free in first seed (52.85, notably even splitting the race) before swimming on Australia’s 800 free relay, where she anchored the Aussies in 1:55.94 to help them win silver behind USA.
On night 6, O’Callaghan swam in the 100 free final, once again using a strong back-half to pass the field on the 2nd 50 and touch first in 52.67. After the race, O’Callaghan revealed she had a leg cramp before the race.
On night 7, O’Callaghan once again pulled relay duties, anchoring Australia’s mixed 400 free relay in 52.03 to not only take gold but break the world record (3:19.38).
On the final night of the meet, O’Callaghan anchored the 400 medley relay in 52.30, touching for 2nd behind the USA.
2022 Commonwealth Games (Birmingham, UK)
O’Callaghan kicked off her meet with a stunning 1:54.01 200 free for silver behind Ariarne Titmus. The swim made her the 6th fastest in history. In the same session, O’Callaghan (52.62) and Emma McKeon (52.21) delivered the two fastest female splits in the field to bring Australia’s 4×100 mixed free relay in for gold, clocking a time of 3:21.18 to establish a new Games Record after the prelim relay went 3:22.34.
In the 4×200 free relay, O’Callaghan clocked a 1:54.80 while the team reaped gold and a new world record behind Titmus’s 1:52.82 anchor leg. In the 100 free, she earned her first individual gold with a 52.63. In the 50 back, she clocked a 27.47 which would have tied the Games Record if not for Kylie mass breaking it a mere .16 seconds before.
She also won gold in the women’s 4×100 free relay and 4×100 medley relays with splits of 52.66 and 52.38 respectively.
2022 Duel in the Pool
O’Callaghan anchored the victorious women’s 4×100 medley relay and the victorious mixed 4×100 medley relay. In the 100 back, she claimed second behind Kaylee McKeown in 59.25. O’callaghan split 27.5 on the backstroke leg of the mixed 4×50 medley relay. In the 50 back skins, O’Callaghan made it through all three rounds alongside McKeown who won the final. Using her back-end speed, she won the 100 free. She also anchored the Aussie 4×100 in the 2×200 vs 4×100 free mixed random relay past Bella Sims for the win.
2022 Australian Short Course Championships (Sydney, Australia)
In the 100 back, O’Callaghan posted a 56.02 for 3rd but qualified for Short Course Worlds because one of the women who beat her was American Beata Nelson. She also posted a 51.50 for 3rd in the 100 free.
2022 Short Course World Championships (Melbourne, Australia)
The team of O’Callaghan (52.19), Madi Wilson (51.28), Meg Harris (52.00), and Emma McKeon (49.96) broke the world record in the women’s 4×100 free relay on night 1. Later on, Wilson (1:53.13), O’Callaghan (1:52.83), Leah Neale (1:52.67), and Lani Pallister (1:52.24) combined for another world record in the women’s 4×200 free relay. O’Callagan was reportedly spotted in tears from debilitating cramping in the abdominal area prior to the final of the women’s 800 freestyle relay
On the same night, O’Callaghan blazed a 55.62 100 back for silver, just .13 behind McKeown. In the women’s 4×50 free relay, O’Callaghan split 24.01 as the Australians took silver.
In the 50 back, O’Callaghan knocked eight one-hundredths off the Oceanian and Australian Record she set in the semis (25.69), which had lowered the previous mark of 25.81 set by Minna Atherton in 2019. Her time was only good enough for a bronze though as Maggie Mac Neil broke the world record and Claire Curzan became the 2nd fastest ever just ahead of O’Callaghan.
In the 4×50 medley relay, O’Callaghan swam a 25.49 50 back to beat out her own Oceanic record time of 25.61 from the individual 50 back finals. She overtook Claire Curzan to become the second-fastest performer of all time in the event. The Australian team of O’Callaghan, Chelsea Hodges, McKeon, and Wilson broke the women’s 4×50 medley relay world record in a time of 1:42.35, taking 0.03 seconds off the United States’ old world record from the 2018 Short Course World Championships.
In the prelims of the women’s 4×100 medley relay, O’Callghan started out strongly with the quickest backstroke opener of the field in 55.81. The finals squad claimed silver.
2023 New South Wales State Open Championships (Sydney, Australia)
O’Callagan posted a strong in-season 1:55.27 200 free. She also had strong backstrokes courtesy of a 27.38 50 back, a 59.41 100 back, and a 2:10.21 200 back, and a decent 400 free with a 4:07.21.
2023 Australian National Championships (Gold Coast, Australia)
O’Callagan topped a strong field that included tons of Australian sprint stalwarts with a world-leading 52.63 100 free. The next day she posted a 58.42 100 back to become the 3rd fastest Australian ever in the event behind Olympic champions McKeown and Emily Seebohm. She posted a 27.42 50 back. In a showdown with Olympic champ Ariarne Titmus, O’Callaghan came out on top with a swift 1:55.15 200 free.
2023 Australian World Championship Trials (Melbourne, Australia)
Facing down an on-fire Kaylee McKeown in the 100 back, O’Callaghan tied her lifetime best with a 58.42 for second, securing her spot at Worlds. The 200 freestyle was a thriller of a race, with Olympians Mollie O’Callaghan and Ariarne Titmus battling all the way to the finish. O’Callaghan touched first, blasting a new lifetime best of 1:53.83 while Titmus settled for silver. The swim made her the 5th fastest in history. In the 100 free, it was O’Callaghan against another titan: Emma McKeon. McKeon led the prelims while O’Callaghan sat in 3rd behind Shayna Jack. In the finals, it was the same top three but O’Callaghan got there first in a super quick 52.48 while McKeon touched 2nd, just .04 back. The swim was a personal best for her by .01. In the 50 free, she finished 4th with a time of 24.64.
Post trials, O’Callaghan injured her knee. “She tweaked it during a stretching session, she was in the water last night and will be going to Worlds but is on a modified program to get her back to full fitness,” according to a statement from Swimming Australia.
2023 World Aquatics Championships (Fukuoka, Japan)
O’Callaghan entered the meet with a cloud of doubt about her status as she had dislocated her knee in training after trials. O’Callaghan opened her meet with a 52.08 to lead off the Aussie 400 free relay in finals. It improves on her world-leading time of 52.48 from trials that was briefly overtaken by Shayna Jack’s 52.28 lead-off on the prelims relay. The swim marked a best time for O’Callaghan and made her the #7 performer in the event. If all that wasn’t enough, the Aussie team: Jack (51.69), Meg Harris (52.29), Emma McKeon (51.90), and O’Callaghan combined for a 3:27.96 to obliterate the world record of 3:29.69 the Aussies set in 2021 by 1.73 seconds.
In the 200 free, O’Callaghan was a relaxed 1:55.68 to lead prelims. In semis, she improved to 1:54.91 to claim 3rd seed in the finals. With most eyes on Ariarne Titmus in the cent of the pool as she out-split the field on every split of the first 150, O’Callaghan was having a brilliant race in her own right. She was 55.94 through the 100 and moved to 2nd with a 28.80 in the 3rd 50. Titmus tightened up down the stretch and O’Callaghan crushed a 28.11 split to storm home to a 1:52.85, a new world record. The time made her just the 2nd woman under 1:53, eclipsing Federica Pellegrini’s 14-year-old 1:52.98. The rest of the finishers were fast too: Titmus was 1:53.01, McIntosh set a new WJR with 1:53.56, and Siobhan Haughey was 1:53.96, perhaps the 1st time a 1:53 has not medaled.
With the 100 free semis earlier in the session, O’Callaghan was a little off her best time leading off the 800 free relay in 1:53.66. It was still the fastest flat start split in the field by over 2 seconds and the 2nd fastest relay leg overall. The rest of her squad brought the relay home to a world record by nearly 2 seconds.
In the 100 free, O’Callaghan was controlled in prelims with a 54.01. In semis, she was the 2nd fastest behind Marrit Steenbergen of the Netherlands with a 52.86. Things looked a little grim for O’Callaghan in the final as she was out in 25.75 and sat back in 7th, but she was only .12 off her best time pace. O’Callaghan stormed home like a freight train, passing every single person in the field. Even Steenbergen, who is known for her 200 free ability and came home the 2nd fastest, was .70 back from O’Callaghan’s back 50 of 26.41. Her time of 52.16 was just off her best time of 52.08 she set on night 1 on the 400 free relay. This brings her fold medal total to 4 and makes her the first woman ever to sweep the 100/200 free.
2024 Australian Olympic Trials (Brisbane, Australia)
In the 100 back, O’Callaghan had a huge swim, becoming just the 4th woman ever to break 58 seconds and become the #4 performer ever with a 57.88 for 2nd behind McKeown. As many expected, O’Callaghan ended up dropping the 100 back from her Olympic lineup, opening the door for Iona Anderson, who placed 3rd at trials, to contest the event.
In the showdown of the meet, Titmus and O’Callaghan faced off in the 200 free. The two were 1-2 in prelims with Titmus clocking a 1:55.50 to O’Callaghan’s 1:55.68. In the final, the two were pedal to the metal. MOC led at the 50, a rarity, with a 26.59 to Titmus’ 26.56. Titmus took the lead on the 2nd 50 with a 28.49 to O’Callaghan’s 28.74 and never let go, splitting 28.82/28.28 versus MOC’s 28.78/28.37. Both swimmers touched well ahead of O’Callaghan’s previous World Record of 1:52.85, with Titmus taking the win in 1:52.23 and MOC touching a little back in 1:52.48.
In the 100 free, O’Callaghan was a solid 52.57 through prelims for the 2nd seed behind Meg Harris’ 52.52. In the final, O’Callaghan was in control, flipping 5th at the 50 with a 25.61 but closing with her typical speed, clocking a 26.72 split to pass all in her way and take the win in 52.33.
