The women's 100 metre freestyle event at the 2025 World Aquatics Championships was held from 31 July to 1 August at the World Aquatics Championships Arena at the Singapore Sports Hub in Kallang, Singapore.

Background Only two athletes from the 2023 World Championships final were returning, leaving opportunities for emerging competitors. 2024 Olympic gold and bronze medalists Sarah Sjöström of Sweden and Siobhán Haughey of Hong Kong were also absent. Australia’s Mollie O’Callaghan entered as the top seed with a time of 52.24, though she had a heavy schedule and recent knee injury. The United States’ Torri Huske, second seed with 52.29, held the world's fastest 2025 time (52.43) and had shown consistent time drops at major meets. Gretchen Walsh, also from the United States, had posted 52.78 in 2025. Defending World Champion Marrit Steenbergen of the Netherlands, seeded at 52.72, and teammate Milou van Wijk were also expected to contest strongly. China’s Wu Qingfeng and Cheng Yujie, alongside Italy’s Sara Curtis and Australian Olivia Wunsch are additional podium contenders.

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 in an approved qualification event. For this event, the "A" standard qualification time was 54.25 seconds. 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 56.15 seconds. 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 timesSwimmerCountryTimeCompetitionSarah Sjöström52.162024 Summer OlympicsMollie O'Callaghan52.242024 Summer OlympicsTorri Huske52.292024 Summer OlympicsSiobhán Haughey52.332024 Summer OlympicsYang Junxuan52.482024 Summer OlympicsMeg Harris52.522024 Australian Olympic TrialsKate Douglass52.562024 United States Olympic TrialsShayna Jack52.652024 Australian Olympic TrialsMarrit Steenbergen52.722024 Eindhoven meetGretchen Walsh52.782025 United States Championships

Records Prior to the competition, the existing world and championship records were as follows.

Heats The heats took place on 31 July 2025 at 10:02.

RankHeatLaneSwimmerNationTimeNotes 1 9 4 Mollie O'Callaghan 53.40 Q 2 7 4 Marrit Steenbergen 53.53 Q 2 8 5 Sara Curtis 53.53 Q 4 9 6 Daria Klepikova    Neutral Athletes B 53.55 Q 5 7 6 Béryl Gastaldello 53.56 Q 6 9 1 Florine Gaspard 53.71 Q 7 7 5 Olivia Wunsch 53.74 WD 8 8 3 Cheng Yujie 53.90 Q 9 8 6 Barbora Seemanová 53.94 Q 10 9 2 Roos Vanotterdijk 53.98 Q 11 8 4 Torri Huske 53.99 Q 12 7 3 Milou van Wijk 54.04 Q 13 8 2 Daria Trofimova    Neutral Athletes B 54.14 Q 14 9 3 Wu Qingfeng 54.15 Q 15 9 7 Nina Holt 54.26 Q 16 7 1 Barbora Janíčková 54.38 Q 17 8 7 Freya Anderson 54.39 R 18 8 1 Emma Virginia Menicucci 54.45 18 8 8 Taylor Ruck 54.45 20 7 8 Sofia Åstedt 54.47 21 7 7 Eva Okaro 54.55 21 9 0 Maria Daza Garcia 54.55 23 7 2 Stephanie Balduccini 54.57 24 8 9 Iris Julia Berger 54.73 25 9 8 Nagisa Ikemoto 54.90 26 7 0 Elisabeth Ebbesen 54.96 27 6 4 Erin Gallagher 55.01 28 6 5 Milana Tapper 55.23 29 9 9 Snæfríður Jórunnardóttir 55.31 30 6 9 Lillian Slušná 55.48 31 6 2 Hur Yeon-kyung 55.58 31 7 9 Li Sum Yiu 55.58 33 6 3 Janja Šegel 55.71 34 6 7 Gloria Muzito 56.04 35 6 1 Lea Polonsky 56.10 36 6 8 Quah Ting Wen 56.44 37 6 6 Danielle Hill 56.59 38 5 4 Andrea Becali 57.05 38 6 0 Isabella Dieffenthaller 57.05 40 5 9 Sara Mose 57.46 41 5 6 Tilly Collymore 57.64 NR 42 5 3 Paige van der Westhuizen 57.70 43 5 5 Anahira McCutcheon 57.76 44 5 7 Mia Millar 57.81 45 5 2 Elisabeth Timmer 58.01 46 4 5 Joselle Mensah 58.98 NR 47 5 1 Zaylie-Elizabeth Thompson 59.45 48 4 4 Riley Miller 59.55 49 2 8 Hiruki de Silva 59.83 50 4 0 Emilia Sandoval 59.88 51 2 0 Mia Laban 59.95 52 5 8 Aunjelique Liddie 59.98 53 4 6 María Fernández 54 5 0 Mikaili Charlemagne 55 4 7 Jovana Kuljača 56 4 2 Asma Lefalher 57 3 3 Davia Richardson 58 4 3 Estela Duran 59 2 3 Adaku Nwandu 60 2 2 Yeva Karapetyan 61 2 7 Aiymkyz Aidaralieva 62 4 8 Jhnayali Tokome-Garap 63 1 3 Osiyokhon Redjapova 64 4 1 Aleka Persaud 65 3 6 Sharmeen Mohd Mharvin 66 3 4 Anastasiya Morginshtern 67 1 4 Jana Al-Tawil 68 3 0 Loane Russet NR 69 3 7 Kestra Kihleng NR 70 3 1 Siwakhile Dlamini 71 3 5 Jasmine Schofield 72 1 6 Amna Thazkiyah Mirsaad 73 3 2 Mashael Al-Ayed 74 4 9 Charissa Panuve 75 1 5 Aarya Maharjan 76 3 9 Amazya Macrooy 77 2 9 Mst Any Akter 78 2 5 Aragsan Mugabo 79 2 4 Iman Kouraogo 80 3 8 Tayamika Chang'anamuno 81 2 1 Ceylia Djeutcha 82 2 6 Djenabou Jolie Bah 8 0 Katarzyna Wasick 9 5 Gretchen Walsh

Semifinals The semifinals took place on 31 July at 19:11.

RankHeatLaneSwimmerNationTimeNotes 1 1 4 Marrit Steenbergen 52.81 Q 2 2 4 Mollie O'Callaghan 52.82 Q 3 1 5 Daria Klepikova    Neutral Athletes B 53.14 Q, NR 4 1 2 Torri Huske 53.21 Q 5 2 6 Cheng Yujie 53.34 Q 6 2 3 Béryl Gastaldello 53.36 Q 7 2 5 Sara Curtis 53.39 Q 8 2 7 Milou van Wijk 53.51 Q 9 2 8 Barbora Janíčková 53.60 10 1 6 Barbora Seemanová 53.72 11 1 3 Florine Gaspard 53.87 11 2 2 Roos Vanotterdijk 53.87 13 1 7 Daria Trofimova    Neutral Athletes B 54.21 14 1 1 Nina Holt 54.31 15 2 1 Wu Qingfeng 54.32 16 1 8 Freya Anderson 54.49

Final The final took place on 1 August at 19:02.

Rank Lane Name Nationality Time Notes 4 Marrit Steenbergen 52.55 5 Mollie O'Callaghan 52.67 6 Torri Huske 52.89 4 8 Milou van Wijk 52.91 5 3 Daria Klepikova    Neutral Athletes B 52.98 NR 6 7 Béryl Gastaldello 53.30 7 2 Cheng Yujie 53.34 8 1 Sara Curtis 53.41

Notes

References