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

The mixed 4 × 100 metre medley relay event at the 2018 Summer Youth Olympics took place on 12 October at the Natatorium in Buenos Aires, Argentina.

## Results
### Heats

The heats were started at 11:18
| Rank | Heat | Lane | Name | Nationality | Time | Notes |
| 1 | 4 | 8 | Peng Xuwei (1:01.64) Sun Jiajun (1:01.60) Hong Jinquan (54.25) Yang Junxuan (55.61) | China | 3:53.10 | Q |
| 2 | 2 | 3 | Miku Kojima (1:03.96) Yu Hanaguruma (1:01.80) Shinnosuke Ishikawa (52.96) Nagisa Ikemoto (55.42) | Japan | 3:54.14 | Q |
| 3 | 4 | 4 | Polina Egorova (1:02.33) Vladislav Gerasimenko (1:01.91) Daniil Markov (54.89) Elizaveta Klevanovich (55.29) | Russia | 3:54.42 | Q |
| 4 | 3 | 4 | Madison Broad (1:02.17) Alexander Milanovich (1:03.12) Joshua Liendo (54.55) Kyla Leibel (55.53) | Canada | 3:55.37 | Q |
| 5 | 2 | 1 | Ingeborg Vassbakk Løyning (1:02.83) André Klippenberg Grindheim (1:04.56) Tomoe Zenimoto Hvas (52.34) Malene Rypestøl (57.60) | Norway | 3:57.33 | Q |
| 6 | 4 | 5 | Rhyan White (1:02.17) Ethan Dang (1:04.62) Jake Johnson (54.30) Kate Douglass (56.37) | United States | 3:57.46 | Q |
| 7 | 3 | 1 | Lila Touili (1:03.35) Clara Basso-Bert (1:09.95) Sergueï Comte (54.02) Jean-Marc Delices (50.48) | France | 3:57.80 | Q |
| 8 | 3 | 8 | Julia Mrozinski (1:03.64) Anna Kroniger (1:11.71) Luca Armbruster (53.15) Rafael Miroslaw (49.57) | Germany | 3:58.07 | Q |
| 9 | 2 | 8 | Kaylee McKeown (1:01.34) Chelsea Hodges (1:10.37) Joseph Jackson (56.63) Ashton Brinkworth (50.07) | Australia | 3:58.41 | |
| 10 | 4 | 7 | Aleksandra Knop (1:03.83) Jan Kałusowski (1:03.70) Jakub Majerski (53.94) Kornelia Fiedkiewicz (57.29) | Poland | 3:58.76 | |
| 11 | 2 | 7 | Björn Seeliger (57.57) Hannah Brunzell (1:11.14) Sara Junevik (1:00.40) Robin Hanson (50.01) | Sweden | 3:59.12 | |
| 12 | 4 | 2 | Fernanda de Goeij (1:02.79) Vitor de Souza (1:04.95) Maria Pessanha (1:01.55) Lucas Peixoto (50.16) | Brazil | 3:59.45 | |
| 13 | 1 | 3 | Anastasia Gorbenko (1:01.69) Gal Cohen Groumi (1:05.78) Lea Polonsky (1:01.85) Denis Loktev (50.36) | Israel | 3:59.68 | |
| 14 | 2 | 4 | Hendrik Duvenhage (57.58) Michael Houlie (1:01.74) Duné Coetzee (1:03.42) Christin Mundell (58.59) | South Africa | 4:01.33 | |
| 15 | 2 | 5 | Natalie Kan (1:04.96) Marcus Mok (1:04.31) Nicholas Lim (55.61) Tinky Ho (57.63) | Hong Kong | 4:02.51 | |
| 16 | 1 | 6 | Noè Ponti (58.16) Elena Onieva Henrich (1:13.75) Antonio Djakovic (54.39) Leoni Richter (57.07) | Switzerland | 4:03.37 | |
| 17 | 1 | 5 | Guillermo Cruz (58.50) Andrés Puente (1:03.72) Miriam Guevara (1:02.08) Taydé Sansores (59.66) | Mexico | 4:03.96 | |
| 18 | 3 | 7 | Alanas Tautkus (57.04) Kotryna Teterevkova (1:09.26) Agnė Šeleikaitė (1:05.77) Arijus Pavlidi (51.95) | Lithuania | 4:04.02 | |
| 19 | 3 | 5 | Juan Méndez (58.27) María Alborzen (1:11.99) Joaquín González (57.72) Julieta Lema (56.41) | Argentina | 4:04.39 | |
| 20 | 3 | 2 | Tatiana Salcuțan (1:02.60) Anastasia Moscenscaia (1:11.36) Nichita Bortnicov (57.80) Ivan Semidetnov (52.98) | Moldova | 4:04.74 | |
| 21 | 3 | 3 | Gan Ching Hwee (1:08.15) Maximillian Ang (1:04.72) Ong Jung Yi (55.10) Christie Chue (57.70) | Singapore | 4:05.67 | |
| 22 | 3 | 6 | Roni Kallström (58.10) Laura Lahtinen (1:13.74) Nea-Amanda Heinola (1:02.75) Alexey Belfer (53.25) | Finland | 4:07.84 | |
| 23 | 2 | 2 | Lucija Šulenta (1:06.30) Nika Čulina (1:13.81) Dominik Karačić (56.66) Ognjen Marić (52.94) | Croatia | 4:09.71 | |
| 24 | 4 | 1 | Anastassiya Rezvantseva (1:05.41) Diana Nazarova (1:20.34) Kirill Shatskov (56.39) Alen Okhotinskiy (53.46) | Kazakhstan | 4:15.60 | |
| 25 | 1 | 4 | Anthony Rincón (57.14) María Román (1:24.79) Valentina Becerra (1:02.54) Juan Morales (53.57) | Colombia | 4:18.04 | |
| 26 | 2 | 6 | Akhmadjon Umurov (1:02.12) Aleksey Sidorchuk (1:05.80) Bibigul Menlibaeva (1:10.40) Natalya Kritinina (1:00.67) | Uzbekistan | 4:18.99 | |
| 27 | 4 | 3 | Trinidad Ardiles (1:05.38) Inés Marín (1:23.60) Benjamin Schnapp (57.98) Martín Valdivieso (55.00) | Chile | 4:21.96 | |

### Final

The final was held at 19:42.
| Rank | Lane | Name | Nationality | Time |
| | 4 | Wang Guanbin (55.31) Sun Jiajun (1:00.22) Lin Xintong (59.52) Yang Junxuan (54.74) | China | 3:49.79 |
| | 3 | Polina Egorova (1:01.98) Anastasia Makarova (1:10.00) Andrei Minakov (51.63) Kliment Kolesnikov (47.85) | Russia | 3:51.46 |
| | 5 | Miku Kojima (1:03.74) Taku Taniguchi (1:01.16) Shinnosuke Ishikawa (51.94) Nagisa Ikemoto (54.90) | Japan | 3:51.74 |
| 4 | 2 | Ingeborg Vassbakk Løyning (1:02.95) André Klippenberg Grindheim (1:03.21) Tomoe Zenimoto Hvas (53.03) Malene Rypestøl (57.56) | Norway | 3:56.75 |
| 5 | 7 | Rhyan White (1:02.18) Ethan Dang (1:04.34) Jake Johnson (54.40) Kate Douglass (55.89) | United States | 3:56.81 |
| 6 | 1 | Lila Touili (1:03.56) Clara Basso-Bert (1:09.49) Sergueï Comte (53.88) Jean-Marc Delices (50.32) | France | 3:57.25 |
| 7 | 6 | Madison Broad (1:02.68) Alexander Milanovich (1:04.86) Joshua Liendo (53.75) Kyla Leibel (56.03) | Canada | 3:57.32 |
| 8 | 8 | Julia Mrozinski (1:03.08) Anna Kroniger (1:12.17) Luca Armbruster (53.24) Rafael Miroslaw (49.39) | Germany | 3:57.88 |