| Rank | Heat | Lane | Name | Nationality | Time | Notes |
| 1 | 7 | 4 | Halsall, FrancescaFrancesca Halsall | England | 24.31 | Q, GR |
| 2 | 8 | 4 | Campbell, CateCate Campbell | Australia | 24.33 | Q |
| 3 | 6 | 4 | Campbell, BronteBronte Campbell | Australia | 24.52 | Q, GR |
| 4 | 7 | 3 | Vanderpool-Wallace, AriannaArianna Vanderpool-Wallace | Bahamas | 24.61 | Q |
| 5 | 8 | 5 | Schlanger, MelanieMelanie Schlanger | Australia | 24.87 | Q |
| 6 | 7 | 5 | Smith, AmyAmy Smith | England | 25.08 | Q |
| 7 | 8 | 3 | Harkin, SianSian Harkin | Scotland | 25.30 | Q |
| 8 | 6 | 5 | Poon, VictoriaVictoria Poon | Canada | 25.38 | Q |
| 9 | 7 | 6 | Williams, MichelleMichelle Williams | Canada | 25.48 | Q |
| 10 | 6 | 3 | Mainville, SandrineSandrine Mainville | Canada | 25.62 | Q |
| 11 | 8 | 6 | Lloyd, JessJess Lloyd | England | 25.64 | Q |
| 12 | 8 | 2 | Maree, TrudiTrudi Maree | South Africa | 25.80 | Q |
| 13 | 6 | 6 | Lim, AmandaAmanda Lim | Singapore | 25.81 | Q |
| 14 | 7 | 7 | Weech, ArielAriel Weech | Bahamas | 25.93 | Q |
| 15 | 6 | 2 | Chui Lai Kwan | Malaysia | 26.00 | Q, NR[3] |
| 16 | 7 | 2 | McCarthy, HannahHannah McCarthy | Wales | 26.12 | Q |
| 17 | 8 | 7 | Chan, MarinaMarina Chan | Singapore | 26.17 | |
| 18 | 7 | 1 | Brunlehner, SylviaSylvia Brunlehner | Kenya | 26.86 | |
| 19 | 6 | 1 | Puamau, CarolineCaroline Puamau | Fiji | 26.87 | |
| 20 | 8 | 1 | Quah Ting Wen | Singapore | 26.90 | |
| 21 | 5 | 7 | Plateau de Maroussen, OliviaOlivia Plateau de Maroussen | Mauritius | 26.99 | |
| 22 | 5 | 2 | Hill, DanielleDanielle Hill | Northern Ireland | 27.23 | |
| 23 | 6 | 7 | Davies, MariMari Davies | Wales | 27.25 | |
| 24 | 3 | 5 | Joachim, IzzyIzzy Joachim | Saint Vincent and the Grenadines | 27.30 | |
| 25 | 5 | 1 | Kinley, LauraLaura Kinley | Isle of Man | 27.34 | |
| 26 | 8 | 8 | Pissaridou, MargaritaMargarita Pissaridou | Cyprus | 27.42 | |
| 27 | 4 | 4 | Lunkuse, JamilaJamila Lunkuse | Uganda | 27.43 | |
| 28 | 4 | 3 | Butcher, CourtneyCourtney Butcher | Guernsey | 27.48 | |
| 29 | 6 | 8 | Passon, FelicityFelicity Passon | Seychelles | 27.52 | |
| 30 | 5 | 6 | Phillip, ElinahElinah Phillip | British Virgin Islands | 27.57 | |
| 31 | 7 | 8 | Firth, BethanyBethany Firth | Northern Ireland | 27.61 | |
| 32 | 5 | 3 | Bethel, RachelRachel Bethel | Northern Ireland | 27.70 | |
| 33 | 4 | 7 | Buadromo, MatelitaMatelita Buadromo | Fiji | 27.75 | |
| 34 | 4 | 5 | Chan Chee, EmilyEmily Chan Chee | Mauritius | 27.83 | |
| 35 | 5 | 8 | Rova, CheyenneCheyenne Rova | Fiji | 27.84 | |
| 36 | 5 | 5 | Howard, JadeJade Howard | Zambia | 27.94 | |
| 37 | 4 | 8 | Tafatatha, JoyceJoyce Tafatatha | Malawi | 28.05 | |
| 38 | 3 | 4 | Paljk, TilkaTilka Paljk | Zambia | 28.20 | |
| 39 | 4 | 2 | Cherebin, OreoluwaOreoluwa Cherebin | Grenada | 28.50 | |
| 40 | 3 | 3 | Vali-Skelton, BarbaraBarbara Vali-Skelton | Papua New Guinea | 28.62 | |
| 41 | 4 | 6 | Prescott, IreneIrene Prescott | Tonga | 28.77 | |
| 42 | 3 | 1 | Phillip, AmarahAmarah Phillip | British Virgin Islands | 28.95 | |
| 43 | 3 | 6 | Linares, ChristinaChristina Linares | Gibraltar | 29.05 | |
| 44 | 4 | 1 | Swayne, OpheliaOphelia Swayne | Ghana | 29.09 | |
| 45 | 3 | 7 | Swan, LiannaLianna Swan | Pakistan | 29.10 | |
| 46 !=46 | 2 | 5 | Foum, MariamMariam Foum | Tanzania | 29.16 | |
| 3 | 8 | Tkatchenko, SavannahSavannah Tkatchenko | Papua New Guinea | |
| 48 !=48 | 2 | 3 | Afoa, EvelinaEvelina Afoa | Samoa | 29.25 | |
| 3 | 2 | Field, AnitaAnita Field | Kenya | |
| 50 | 2 | 6 | Wall, RachelRachel Wall | Antigua and Barbuda | 29.35 | |
| 51 | 1 | 4 | Khan, KiranKiran Khan | Pakistan | 29.46 | |
| 52 | 5 | 4 | Millar, KirstieKirstie Millar | Malawi | 29.50 | |
| 53 | 2 | 4 | George, OnikaOnika George | Guyana | 29.55 | |
| 54 | 1 | 5 | Flynn, JocelynJocelyn Flynn | Papua New Guinea | 29.80 | |
| 55 | 2 | 2 | Moshi, MagdalenaMagdalena Moshi | Tanzania | 29.97 | |
| 56 | 1 | 3 | Lawrence, AdoraAdora Lawrence | Saint Vincent and the Grenadines | 31.23 | |
| 57 | 2 | 7 | Shajan, AminathAminath Shajan | Maldives | 31.25 | |