# Swimming at the 2019 World Aquatics Championships – Women's 4 × 100 metre medley relay

The Women's 4 × 100 metre medley relay competition at the 2019 World Championships was held on 28 July 2019.

## Records

Prior to the competition, the existing world and championship records were as follows.
| World record | United States | 3:51.55 | Budapest, Hungary | 30 July 2017 |
| Competition record | United States | 3:51.55 | Budapest, Hungary | 30 July 2017 |

## Results
### Heats

The heats were held on 28 July at 11:07.
| Rank | Heat | Lane | Nation | Swimmers | Time | Notes |
| 1 | 2 | 4 | United States | Olivia Smoliga (58.79) Melanie Margalis (1:06.40) Katie McLaughlin (57.15) Mallory Comerford (53.05) | 3:55.39 | Q |
| 2 | 3 | 4 | Australia | Kaylee McKeown (59.44) Jessica Hansen (1:06.99) Brianna Throssell (58.28) Madison Wilson (53.48) | 3:58.19 | Q |
| 3 | 2 | 6 | Italy | Margherita Panziera (1:00.56) Arianna Castiglioni (1:06.68) Ilaria Bianchi (57.54) Federica Pellegrini (53.57) | 3:58.35 | Q |
| 4 | 3 | 3 | Canada | Kylie Masse (58.98) Kierra Smith (1:08.61) Rebecca Smith (58.04) Taylor Ruck (53.00) | 3:58.63 | Q |
| 5 | 3 | 7 | China | Fu Yuanhui (1:00.01) Yu Jingyao (1:07.28) Wang Yichun (58.13) Zhu Menghui (53.84) | 3:59.26 | Q |
| 6 | 2 | 1 | Sweden | Michelle Coleman (1:01.41) Sophie Hansson (1:07.33) Louise Hansson (57.43) Sarah Sjöström (53.23) | 3:59.40 | Q |
| 7 | 3 | 6 | Great Britain | Georgia Davies (1:00.32) Molly Renshaw (1:08.00) Alys Thomas (58.77) Anna Hopkin (52.65) | 3:59.74 | Q |
| 8 | 2 | 5 | Japan | Natsumi Sakai (1:00.16) Reona Aoki (1:07.65) Hiroko Makino (58.17) Rika Omoto (53.89) | 3:59.87 | Q |
| 9 | 2 | 2 | Germany | Laura Riedemann (1:00.20) Anna Elendt (1:08.74) Angelina Köhler (57.95) Jessica Steiger (54.02) | 4:00.91 | |
| 10 | 3 | 2 | Netherlands | Kira Toussaint (1:00.04) Tes Schouten (1:08.45) Kim Busch (59.90) Femke Heemskerk (53.03) | 4:01.42 | |
| 11 | 3 | 8 | Switzerland | Nina Kost (1:02.49) Lisa Mamie (1:06.80) Alexandra Touretski (58.68) Maria Ugolkova (53.88) | 4:01.85 | NR |
| 12 | 3 | 5 | Russia | Daria Vaskina (1:01.08) Anna Belousova (1:08.47) Svetlana Chimrova (58.33) Daria S Ustinova (54.38) | 4:02.26 | |
| 13 | 1 | 5 | South Korea | Im Da-sol (1:00.44) Back Su-yeon (1:08.70) Park Ye-rin (58.84) Jeong So-eun (55.40) | 4:03.38 | NR |
| 14 | 2 | 7 | Hong Kong | Stephanie Au (1:01.12) Yeung Jamie Zhen Mei (1:08.92) Chan Kin Lok (1:00.45) Siobhán Haughey (53.03) | 4:03.52 | |
| 15 | 2 | 8 | Poland | Alicja Tchórz (1:00.97) Weronika Hallmann (1:08.88) Paulina Nogaj (59.51) Katarzyna Wasick (54.91) | 4:04.27 | |
| 16 | 2 | 3 | Denmark | Mie Nielsen (1:01.79) Matilde Schroder (1:08.74) Jeanette Ottesen (58.55) Julie Kepp Jensen (55.25) | 4:04.33 | |
| 17 | 2 | 0 | South Africa | Mariella Venter (1:02.84) Tatjana Schoenmaker (1:07.16) Tayla Lovemore (59.34) Emma Chelius (55.78) | 4:05.12 | |
| 18 | 1 | 3 | Finland | Mimosa Jallow (1:01.20) Ida Hulkko (1:07.35) Jenna Laukkanen (1:00.53) Laura Lahtinen (56.42) | 4:05.50 | |
| 19 | 3 | 1 | Hungary | Katalin Burián (1:00.83) Anna Sztankovics (1:08.96) Liliána Szilágyi (59.25) Evelyn Verrasztó (56.57) | 4:05.61 | |
| 20 | 1 | 4 | Turkey | Ekaterina Avramova (1:01.95) Viktoriya Zeynep Güneş (1:09.01) Aleyna Özkan (59.42) Selen Özbilen (55.34) | 4:05.72 | NR |
| 21 | 3 | 0 | Singapore | Quah Jing Wen (1:05.07) Christie Chue (1:11.02) Quah Ting Wen (59.95) Cherlyn Yeoh (55.63) | 4:11.67 | |

### Final

The final was held on 28 July at 21:56.
| Rank | Lane | Nation | Swimmers | Time | Notes |
| | 4 | United States | Regan Smith (57.57 WR) Lilly King (1:04.81) Kelsi Dahlia (56.16) Simone Manuel (51.86) | 3:50.40 | WR |
| | 5 | Australia | Minna Atherton (59.06) Jessica Hansen (1:06.08) Emma McKeon (56.32) Cate Campbell (51.96) | 3:53.42 | |
| | 6 | Canada | Kylie Masse (59.12) Sydney Pickrem (1:06.42) Maggie MacNeil (55.56) Penny Oleksiak (52.48) | 3:53.58 | NR |
| 4 | 3 | Italy | Margherita Panziera (59.77) Martina Carraro (1:06.87) Elena Di Liddo (57.33) Federica Pellegrini (52.53) | 3:56.50 | NR |
| 5 | 2 | China | Chen Jie (1:00.89) Yu Jingyao (1:06.42) Zhang Yufei (56.44) Yang Junxuan (53.36) | 3:57.11 | |
| 6 | 8 | Japan | Natsumi Sakai (59.48) Reona Aoki (1:06.58) Hiroko Makino (58.22) Rika Omoto (53.86) | 3:58.14 | |
| 7 | 7 | Sweden | Michelle Coleman (1:01.42) Sophie Hansson (1:07.20) Louise Hansson (57.23) Sarah Sjöström (52.54) | 3:58.39 | |
| 8 | 1 | Great Britain | Georgia Davies (59.55) Molly Renshaw (1:07.72) Alys Thomas (58.56) Freya Anderson (53.55) | 3:59.38 | |