Heat 6
mercredi 12 décembre 2018, 03h33 GMT – 03h33 GMT
| Nom | Équipe | Temps | |
|---|---|---|---|
| 1 |  Caeleb Dressel | United States | 49.23″ |
| 2 |  Piero Codia | Italy | + 0.84″ |
| 3 |  Takeshi Kawamoto | Japan | + 1.11″ |
| 4 |  Deividas Margevicius | Lithuania | + 2.02″ |
| 5 |  Konrad Czerniak | Poland | + 2.05″ |
| 6 |  Ümit Can Güres | Turkey | + 2.18″ |
| 7 | Ryan Coetzee | South Africa | + 2.42″ |
| 8 |  Leonardo de Deus | Brazil | + 2.46″ |
| 9 | Riku Pöytäkivi | Finland | + 2.67″ |
| 10 | Sascha Subarsky | Austria | + 3.3″ |