The girls' 400 metre freestyle event at the 2018 Summer Youth Olympics took place on 12 October at the Natatorium in Buenos Aires, Argentina.
Results Heats The heats were started at 10:52.Heats results Rank Heat Lane Name Nationality Time Notes 1 4 4 Ajna Késely 4:10.74 Q 2 3 4 Delfina Pignatiello 4:11.86 Q 3 4 5 Marlene Kahler 4:13.10 Q 4 2 5 Nicole Oliva 4:16.72 Q 5 3 2 Duné Coetzee 4:16.73 Q 6 4 7 Kaitlynn Sims 4:16.91 Q 7 4 1 Delfina Dini 4:17.00 Q 8 3 8 Andrea Galisteo 4:17.07 Q 9 4 8 Erika Fairweather 4:17.43 10 2 4 Gan Ching Hwee 4:17.86 11 3 3 Celine Rieder 4:18.10 12 3 6 Rafaela Raurich 4:18.71 13 3 5 Petra Barócsai 4:18.95 14 3 7 Tinky Ho 4:19.49 15 4 6 Maddie Donohoe 4:19.54 16 2 3 Malene Rypestøl 4:21.28 17 3 1 Aleksandra Knop 4:22.09 18 4 2 Kate Beavon 4:22.48 19 4 3 Anja Crevar 4:22.89 20 2 6 Samantha Bello 4:23.27 21 2 1 Ieva Maļuka 4:24.64 22 2 2 Arianna Valloni 4:26.87 23 2 7 Alexandra Frazão 4:27.00 24 1 4 Sandy Atef 4:30.88 25 1 5 Natalia Kuipers 4:45.60 26 1 3 Katie Rock 4:50.72
Final The final was held at 19:13.Final results Rank Lane Name Nationality Time Notes 4 Ajna Késely 4:07.14 5 Delfina Pignatiello 4:10.40 3 Marlene Kahler 4:12.48 4 2 Duné Coetzee 4:15.27 5 7 Kaitlynn Sims 4:15.53 6 6 Nicole Oliva 4:16.61 7 8 Andrea Galisteo 4:16.91 8 1 Delfina Dini 4:19.25
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