The women's 100 metre backstroke event at the 2025 World Aquatics Championships was held from 28 to 29 July 2025 at the World Aquatics Championships Arena at the Singapore Sports Hub in Kallang, Singapore.
Background The event is expected to center on the rivalry between Regan Smith of the United States and Kaylee McKeown of Australia, who have dominated the event since 2020. The two have alternated ownership of the world record, with Smith currently holding it at 57.13 from the 2024 U.S. Olympic Trials, while McKeown won Olympic gold in Paris with 57.33. Both have produced sub-58 times this season, Smith leading with 57.46 and McKeown at 57.65. Other contenders include Katharine Berkoff of the United States, a 2024 Olympic bronze medalist with a 57.83 best, and Canada’s Kylie Masse, a consistent international medalist with a 57.70 lifetime best. Several rising athletes, including Carmen Weiler of Spain and Taylor Ruck of Canada, may also challenge for podium positions.
Qualification Each National Federation was permitted to enter a maximum of two qualified athletes in each individual event, but they could do so only if both of them had attained the "A" standard qualification time. For this event, the "A" standard qualification time was 1:00.46. Federations could enter one athlete into the event if they met the "B" standard qualification time. For this event, the "B" standard qualification time was 1:02.58. Athletes could also enter the event if they had met an "A" or "B" standard in a different event and their Federation had not entered anyone else. Additional considerations applied to Federations who had few swimmers enter through the standard qualification times. Federations in this category could at least enter two men and two women to the competition, all of whom could enter into up to two events. +Top 10 fastest qualification timesSwimmerCountryTimeCompetitionRegan Smith57.132024 United States Olympic TrialsKaylee McKeown57.332024 Summer OlympicsKatharine Berkoff57.832024 United States Olympic TrialsMollie O'Callaghan57.882024 Australian Olympic TrialsKylie Masse57.942024 Canadian Olympic TrialsIona Anderson58.432024 Australian Olympic TrialsKennedy Noble58.552024 United States Olympic TrialsLeah Shackley58.602025 United States ChampionshipsClaire Curzan58.602025 United States ChampionshipsEmma Terebo58.792024 French Elite
Records Prior to the competition, the existing world and championship records were as follows.
The following record was established during the competition: Date Event Swimmer Nation Time Record 29 July Final Kaylee McKeown 57.16 CR
Heats The heats took place on 28 July at 10:02.
RankHeatLaneSwimmerNationTimeNotes 1 6 4 Regan Smith 58.20 Q 2 4 4 Katharine Berkoff 58.55 Q 3 5 4 Kaylee McKeown 58.57 Q 4 5 2 Peng Xuwei 59.34 Q 5 4 3 Wan Letian 59.35 Q 6 5 3 Roos Vanotterdijk 59.37 Q 7 4 6 Mary-Ambre Moluh 59.47 Q 8 4 5 Taylor Ruck 59.55 Q 9 6 5 Kylie Masse 59.71 Q 10 6 2 Hannah Fredericks 59.80 Q 11 5 5 Carmen Weiler 59.86 Q 11 6 3 Marrit Steenbergen 59.86 Q 13 5 8 Anastasiya Shkurdai Neutral Athletes A Q 14 5 6 Pauline Mahieu Q 15 5 1 Kim Seung-won Q 16 4 7 Alina Gaifutdinova Neutral Athletes B Q 17 4 2 Adela Piskorska 18 6 6 Danielle Hill 19 6 7 Maaike de Waard 20 5 7 Miranda Grana 21 4 1 Anita Gastaldi 22 6 1 Hanna Rosvall 23 6 0 Camila Rebelo 24 3 6 Gabriela Georgieva 25 4 0 Aviv Barzelay 26 4 8 Lora Komoróczy 27 5 0 Schastine Tabor 28 6 9 Fanny Teijonsalo 29 6 8 Amber George 30 4 9 Xeniya Ignatova 31 5 9 Justine Murdock 32 3 3 Maari Randväli 33 3 7 Cindy Cheung 34 3 4 Levenia Sim 35 3 1 Andrea Berrino 36 3 2 Zuri Ferguson 37 3 0 Laurent Estrada 38 3 5 Janja Šegel 39 2 4 Elizabeth Jiménez 40 3 8 Natalia Zaiteva 41 2 5 Saovanee Boonamphai 42 3 9 Abril Aunchayna 43 2 6 Anishta Teeluck 44 2 8 Taline Mourad 45 2 3 Carolina Cermelli 46 2 2 Amani Al-Obaidly 47 2 9 Emilia Sandoval 48 1 4 Minagi Rupesinghe 49 2 1 Lara Giménez 50 2 7 Enkh-Amgalangiin Ariuntamir 51 1 5 Aynura Primova NR 52 1 6 Parizod Abdukarimova 53 1 3 Kaila Dacruz 54 1 7 Bjarta í Lágabø 55 2 0 Erina Idrizaj 56 1 2 Amna Thazkiyah Mirsaad NR
Semifinals The semifinals took place on 28 July at 19:53.
RankHeatLaneSwimmerNationTimeNotes 1 2 4 Regan Smith 58.21 Q 2 2 5 Kaylee McKeown 58.44 Q 3 2 2 Kylie Masse 58.66 Q 4 1 4 Katharine Berkoff 58.79 Q 5 1 6 Taylor Ruck 59.18 Q 6 1 5 Peng Xuwei 59.19 Q 7 2 6 Mary-Ambre Moluh 59.35 Q 8 1 1 Pauline Mahieu 59.56 SO 8 2 3 Wan Letian 59.56 SO 10 1 3 Roos Vanotterdijk 59.63 11 1 2 Hannah Fredericks 59.73 12 2 7 Carmen Weiler 59.92 13 1 8 Alina Gaifutdinova Neutral Athletes B 59.93 14 1 7 Marrit Steenbergen 59.94 15 2 1 Anastasiya Shkurdai Neutral Athletes A 16 2 8 Kim Seung-won
Swim-off The swim-off was started on 28 July at 20:39.
Rank Lane Name Nationality Time Notes 1 4 Pauline Mahieu 59.28 Q 2 5 Wan Letian
Final The final took place on 29 July at 19:50.
Rank Lane Name Nationality Time Notes 5 Kaylee McKeown 57.16 CR, OC 4 Regan Smith 57.35 6 Katharine Berkoff 58.15 4 3 Kylie Masse 58.42 5 7 Peng Xuwei 59.10 6 8 Pauline Mahieu 59.48 7 2 Taylor Ruck 59.59 8 1 Mary-Ambre Moluh 59.60
References