# Swimming at the 2018 Summer Youth Olympics – Mixed 4 × 100 metre freestyle relay

The mixed 4 × 100 metre freestyle relay event at the 2018 Summer Youth Olympics took place on 7 October at the Natatorium in Buenos Aires, Argentina.

## Results
### Heats

The heats were started at 11:27.
| Rank | Heat | Lane | Name | Nationality | Time | Notes |
| 1 | 1 | 3 | Lucas Peixoto (50.20) Ana Vieira (55.91) André Calvelo (49.64) Rafaela Raurich (55.17) | Brazil | 3:30.92 | Q |
| 2 | 3 | 7 | Denis Loktev (50.48) Gal Cohen Groumi (50.88) Anastasia Gorbenko (55.38) Lea Polonsky (56.83) | Israel | 3:33.57 | Q |
| 3 | 3 | 4 | Shen Jiahao (51.01) Hong Jinquan (50.61) Lin Xintong (56.58) Yang Junxuan (55.56) | China | 3:33.76 | Q |
| 4 | 3 | 3 | Rafael Miroslaw (50.27) Luca Armbruster (51.41) Angelina Köhler (56.75) Julia Mrozinski (55.66) | Germany | 3:34.09 | Q |
| 5 | 2 | 4 | Ashton Brinkworth (50.36) Joseph Jackson (51.43) Michaela Ryan (56.18) Abbey Webb (56.51) | Australia | 3:34.48 | Q |
| 6 | 1 | 4 | Shinnosuke Ishikawa (52.09) Nagisa Ikemoto (54.52) Mayuka Yamamoto (55.39) Taku Taniguchi (53.95) | Japan | 3:35.95 | Q |
| 7 | 1 | 5 | Jakub Kraska (50.08) Jakub Majerski (50.19) Kornelia Fiedkiewicz (57.39) Karolina Jurczyk (59.03) | Poland | 3:36.69 | Q |
| 8 | 2 | 3 | Daniil Markov (50.28) Vladislav Gerasimenko (51.83) Daria Vaskina (57.20) Anastasia Makarova (57.67) | Russia | 3:36.98 | Q |
| 9 | 3 | 6 | Michael Pickett (50.77) Erika Fairweather (56.53) Gina Galloway (58.90) Zac Reid (51.32) | New Zealand | 3:37.52 | |
| 10 | 3 | 5 | Antonio Djakovic (50.77) Noè Ponti (50.85) Leoni Richter (57.30) Elena Onieva Henrich (59.56) | Switzerland | 3:38.48 | |
| 11 | 2 | 7 | Joshua Liendo (52.23) Finlay Knox (52.61) Kyla Leibel (55.08) Nina Kucheran (59.37) | Canada | 3:39.29 | |
| 12 | 3 | 1 | Ong Jung Yi (53.41) Maximillian Ang (53.03) Gan Ching Hwee (58.59) Christie Chue (56.44) | Singapore | 3:41.47 | |
| 13 | 3 | 8 | Gabriel Nortje (51.60) Hendrik Duvenhage (53.13) Duné Coetzee (57.95) Kate Beavon (59.28) | South Africa | 3:41.96 | |
| 14 | 2 | 6 | Tinky Ho (57.75) Marcus Mok (53.37) Nicholas Lim (52.37) Natalie Kan (58.60) | Hong Kong | 3:42.09 | |
| 15 | 3 | 2 | Joaquín González (53.37) Juan Méndez (54.51) Julieta Lema (55.82) Delfina Dini (59.18) | Argentina | 3:42.88 | |
| 16 | 1 | 6 | Park Jung-hun (52.60) Lee Yoo-yeon (49.71) Wang Hee-song (1:00.35) Yun Eun-sol (1:00.23) | South Korea | 3:42.89 | |
| 17 | 2 | 1 | Marcos Gil (53.36) Ferran Julià (53.23) Tamara Frías (57.83) Andrea Galisteo (58.73) | Spain | 3:43.15 | |
| 18 | 2 | 8 | Will Barao (52.95) Ethan Dang (52.84) Maddie Donohoe (58.72) Kate Douglass (59.17) | United States | 3:43.68 | |
| 19 | 2 | 2 | Andrés Puente (54.80) Taydé Sansores (59.78) Miriam Guevara (1:00.67) Guillermo Cruz (50.68) | Mexico | 3:45.93 | |
| 20 | 2 | 5 | Martín Valdivieso (55.31) Inés Marín (59.21) Trinidad Ardiles (1:03.77) Benjamin Schnapp (53.27) | Chile | 3:51.56 | |

### Final

The final was held at 18:51.
| Rank | Lane | Name | Nationality | Time |
| | 8 | Kliment Kolesnikov (48.17) Andrei Minakov (49.60) Polina Egorova (55.71) Elizaveta Klevanovich (55.02) | Russia | 3:28.50 |
| | 4 | Lucas Peixoto (50.30) Ana Vieira (55.93) André Calvelo (48.66) Rafaela Raurich (55.24) | Brazil | 3:30.13 |
| | 3 | Shen Jiahao (50.83) Hong Jinquan (50.46) Lin Xintong (55.44) Yang Junxuan (53.72) | China | 3:30.45 |
| 4 | 6 | Rafael Miroslaw (50.49) Luca Armbruster (51.21) Angelina Köhler (56.09) Julia Mrozinski (55.24) | Germany | 3:33.03 |
| 5 | 1 | Jakub Kraska (49.12) Jakub Majerski (50.23) Kornelia Fiedkiewicz (57.03) Aleksandra Knop (56.70) | Poland | 3:33.08 |
| 6 | 2 | Ashton Brinkworth (50.61) Joseph Jackson (51.56) Michaela Ryan (56.14) Abbey Webb (55.72) | Australia | 3:34.03 |
| 7 | 7 | Keisuke Yoshida (51.34) Taku Taniguchi (52.67) Mayuka Yamamoto (55.53) Nagisa Ikemoto (54.64) | Japan | 3:34.18 |
| | 5 | Denis Loktev (50.56) Gal Cohen Groumi (50.41) Lea Polonsky (57.03) Anastasia Gorbenko | Israel | DSQ |