| Date | 11 October 2018 — 19:14 | |
|---|---|---|
| Status | YOG | |
| Location | Natatorium, Parque Olímpico de la Juventud, Villa Soldati, Buenos Aires | |
| Participants | 24 from 6 countries | |
| Format | Final round only. | |
| Pos | Competitors | NOC | Time | ||||||
|---|---|---|---|---|---|---|---|---|---|
| 1 | Russian Federation |  RUS | 3:45.26 | Gold | |||||
| Yelizaveta Klevanovich • Anastasiya Makarova • Darya Vaskina • Polina Yegorova | |||||||||
| 2 | Brazil |  BRA | 3:47.20 | Silver | |||||
| Rafaela Raurich • Ana Vieira • Maria Pessanha • Fernanda de Goeij | |||||||||
| 3 | Japan |  JPN | 3:49.27 | Bronze | |||||
| Miku Kojima • Mayuka Yamamoto • Nagisa Ikemoto • Shiori Asaba | |||||||||
| 4 | People's Republic of China |  CHN | 3:53.19 | ||||||
| Yang Junxuan • Peng Xuwei • Zheng Muyan • Lin Xintong | |||||||||
| 5 | United States |  USA | 3:53.32 | ||||||
| Kate Douglass • Rhyan White • Maddie Donohoe • Kaitlynn Sims | |||||||||
| 6 | South Africa |  RSA | 3:57.40 | ||||||
| Duné Coetzee • Christin Mundell • Kate Beavon • Mariella Venter | |||||||||
| Australia |  AUS | – | |||||||
