Jack was born in Brisbane. She started swimming at the age of 18 months, after her parents thought it would be helpful to teach her and her siblings how to be safe in water. She grew to enjoy the experience[4] and at age 10, told her parents she wanted to be an Olympican.[5]
At the2014 Junior Pan Pacific Swimming Championships, held in August inKihei,United States, 15-year-old Jack won a gold medal in the 4×100 meter freestyle relay with aChampionships record time of 3:39.73, the gold medal in the 100 meter freestyle with a 54.82, the silver medal in the 200 meter freestyle with a 1:59.48, a silver medal in the 4×200 meter freestyle relay, and placed fifth in the 50 meter freestyle.[6]
Jack pulled out of the2019 World Aquatics Championships days before it started, citing "personal reasons". It was later revealed that Jack had tested positive for the anabolic agent ligandrol, which is popular with bodybuilders, during an out-of-competition test held by theAustralian Sports Anti-Doping Authority (ASADA); a follow-up sample further confirmed the banned substance in her system, and she was subsequently suspended bySwimming Australia and investigated by ASADA.[7][8][9] She posted on Instagram saying that she "would never intentionally take a banned substance that would disrespect my sport and jeopardise my career".[10][11] The investigation by ASADA was ongoing as of 29 July 2019.[8][12]
The result of the investigation was unintentional ingestion of ligandrol by Jack and a 24-month suspension by theCourt of Arbitration for Sport running from 12 July 2019 through 11 July 2021 for the anti-doping rule violation.[2] In September 2021, after Jack served the entirety of the imposed suspension, the Court of Arbitration for Sport upheld the suspension as served in full when challenged bySport Integrity Australia and that Jack could return to competition.[3]
In May, at the2022 Australian Swimming Championships, held inAdelaide, Jack achieved 2022 World Aquatics Championships and 2022 Commonwealth Games qualifying times in two individual events, winning the 50 metre freestyle with a time of 24.14 seconds, and placing second in the 100 metre freestyle behindMollie O'Callaghan with a time of 52.60 seconds.[13]
In the4×100 metre freestyle relay at the2022 Commonwealth Games, held inBirmingham,England, Jack helped win the gold medal in a time of 3:30.64 by splitting a 52.72 for the second leg of the relay in the final.[16] For the50 metre freestyle, she swam a time of 24.36 seconds in the final to win the bronze medal, securing the final podium spot by finishing 0.42 seconds ahead of fourth-place finisherEmma Chelius ofSouth Africa.[17] In the100 metre freestyle, she finished 0.25 seconds behind gold medalist Mollie O'Callaghan with a time of 52.88 seconds to win the silver medal.[18] On 10 August, following her medal-winning performances at the 2022 Commonwealth Games, Jack was named to the 2022Duel in the Pool roster for Team Australia.[19]
At the2023 Australian Swimming Championships, inGold Coast, Queensland, Jack won the silver medal in the 100-metre freestyle with a2023 World Aquatics Championships qualifying time of 52.64 seconds, finishing 0.01 seconds behind gold medalist Mollie O'Callaghan and 0.58 seconds ahead of the next-fastest competitor. On the second day, she won the gold medal in the 50 metre freestyle with a World Championships qualifying time of 24.45 seconds. On the fourth of four days, she won the bronze medal in the 200 metre freestyle with a 1:55.37.[20]
Jack is engaged to Australian hockey playerJoel Rintala.[24] She was awarded anOrder of Australia in 2025 for her service to sport as a gold medallist at the Paris Olympic Games 2024.[25]
Legend:WR –World record;OC –Oceanian record;NR –Australian record; Records not set in finals:h – heat;sf – semifinal;r – relay 1st leg;rh – relay heat 1st leg;b – B final;† – en route to final mark;tt – time trial
^"Australian swimmer Shayna Jack fails doping test".The Guardian. 27 July 2019. "During a world swimming titles campaign highlighted by Mack Horton's anti-doping stance, Australia's Shayna Jack has tested positive for a banned substance."
^ab"Shayna Jack: The swimming scandal that has embarrassed Australia".BBC News. 29 July 2019. Retrieved29 July 2019. "Queensland swimmer Shayna Jack announced on Sunday that she had tested positive for anabolic agent Ligandrol – which is popular with bodybuilders – in late June and that a follow-up sample has confirmed the banned substance."
