# Swimming at the 2017 World Aquatics Championships – Women's 4 × 100 metre medley relay

The Women's 4 × 100 metre medley relay competition at the 2017 World Championships was held on 30 July 2017.

## Records

Prior to the competition, the existing world and championship records were as follows.
| World record | United States | 3:52.05 | London, Great Britain | 4 August 2012 |
| Competition record | China | 3:52.19 | Rome, Italy | 1 August 2009 |
The following new records were set during this competition.
| Date | Event | Nation | Time | Record |
| 30 July | Final | United States | 3:51.55 | WR |

## Results
### Heats

The heats were held at 10:14.
| Rank | Heat | Lane | Nation | Swimmers | Time | Notes |
| 1 | 2 | 4 | United States | Olivia Smoliga (59.52) Katie Meili (1:05.17) Sarah Gibson (58.36) Mallory Comerford (52.90) | 3:55.95 | Q |
| 2 | 2 | 5 | China | Fu Yuanhui (1:00.04) Shi Jinglin (1:06.55) Zhang Yufei (57.50) Zhu Menghui (53.03) | 3:57.12 | Q |
| 3 | 1 | 5 | Canada | Kylie Masse (58.86) Kierra Smith (1:07.20) Rebecca Smith (57.75) Sandrine Mainville (53.36) | 3:57.17 | Q |
| 4 | 2 | 3 | Russia | Anastasia Fesikova (59.61) Natalia Ivaneeva (1:06.89) Svetlana Chimrova (57.62) Veronika Popova (53.41) | 3:57.53 | Q |
| 5 | 1 | 4 | Australia | Holly Barratt (59.68) Jessica Hansen (1:07.10) Brianna Throssell (58.52) Shayna Jack (53.44) | 3:58.74 | Q |
| 6 | 2 | 6 | Italy | Margherita Panziera (1:01.04) Arianna Castiglioni (1:06.99) Ilaria Bianchi (57.56) Federica Pellegrini (54.44) | 4:00.03 | Q |
| 7 | 2 | 8 | Sweden | Ida Lindborg (1:01.24) Sophie Hansson (1:08.62) Louise Hansson (58.29) Michelle Coleman (53.29) | 4:01.44 | Q |
| 8 | 1 | 3 | Great Britain | Georgia Davies (1:00.23) Sarah Vasey (1:07.96) Alys Thomas (59.84) Freya Anderson (53.75) | 4:01.78 | Q |
| 9 | 2 | 2 | Czech Republic | Simona Baumrtová (1:00.13) Martina Moravčíková (1:07.76) Lucie Svěcená (59.18) Anna Kolářová (55.16) | 4:02.23 | NR |
| 10 | 1 | 2 | Hungary | Katalin Burián (1:00.62) Anna Sztankovics (1:08.75) Liliána Szilágyi (58.32) Flóra Molnár (55.39) | 4:03.08 | NR |
| 11 | 1 | 8 | Finland | Mimosa Jallow (1:01.43) Jenna Laukkanen (1:07.06) Kaisla Kollanus (1:02.43) Lotta Nevalainen (55.46) | 4:06.38 | |
| 12 | 2 | 1 | New Zealand | Bobbi Gichard (1:01.63) Natasha Lloyd (1:09.35) Helena Gasson (1:00.31) Gabrielle Fa'amausili (55.80) | 4:07.09 | |
| 13 | 1 | 6 | Hong Kong | Claudia Lau (1:02.56) Siobhán Haughey (1:07.62) Chan Kin Lok (1:00.22) Sze Hang Yu (57.00) | 4:07.40 | |
| 14 | 1 | 7 | Israel | Andrea Murez (1:02.45) Amit Ivry (1:11.27) Keren Siebner (59.65) Zohar Shikler (56.98) | 4:10.35 | |
| 15 | 1 | 1 | Slovakia | Karolina Hájková (1:03.57) Andrea Podmaníková (1:10.86) Barbora Mišendová (1:01.62) Katarína Listopadová (55.98) | 4:12.03 | |
| 16 | 2 | 0 | Mexico | Fernanda González (1:02.25) Esther González (1:10.86) María José Mata (1:02.41) Liliana Ibáñez (56.52) | 4:12.04 | |
| 17 | 2 | 7 | South Africa | Samantha Randle (1:05.85) Kaylene Corbett (1:10.65) Erin Gallagher (1:01.58) Emma Chellius (57.39) | 4:15.47 | |

### Final

The final was held at 19:07.
| Rank | Lane | Nation | Swimmers | Time | Notes |
| | 4 | United States | Kathleen Baker (58.54) Lilly King (1:04.48) Kelsi Worrell (56.30) Simone Manuel (52.23) | 3:51.55 | WR |
| | 6 | Russia | Anastasia Fesikova (58.96) Yuliya Yefimova (1:04.03) Svetlana Chimrova (56.99) Veronika Popova (53.40) | 3:53.38 | ER |
| | 2 | Australia | Emily Seebohm (58.53) Taylor McKeown (1:06.29) Emma McKeon (56.78) Bronte Campbell (52.69) | 3:54.29 | |
| 4 | 3 | Canada | Kylie Masse (58.31) Kierra Smith (1:06.57) Penny Oleksiak (56.90) Chantal Van Landeghem (53.08) | 3:54.86 | NR |
| 5 | 1 | Sweden | Ida Lindborg (1:01.56) Jennie Johansson (1:05.76) Sarah Sjöström (55.03) Michelle Coleman (52.93) | 3:55.28 | |
| 6 | 5 | China | Fu Yuanhui (1:00.52) Shi Jinglin (1:06.16) Zhang Yufei (57.39) Zhu Menghui (53.62) | 3:57.69 | |
| 7 | 8 | Great Britain | Kathleen Dawson (1:00.24) Sarah Vasey (1:07.06) Charlotte Atkinson (58.29) Freya Anderson (53.92) | 3:59.51 | |
| 8 | 7 | Italy | Margherita Panziera (1:01.12) Arianna Castiglioni (1:06.55) Ilaria Bianchi (57.64) Federica Pellegrini (54.67) | 3:59.98 | |