| Games: | World Aquatics Championships |
| Nf: | LCA |
| Nfname: | St. Lucia Aquatic Federation |
| Year: | 2019 |
| Flagcaption: | Flag of Saint Lucia |
| Location: | Gwangju, South Korea |
| Competitors: | 4 |
| Sports: | 1 |
| Gold: | 0 |
| Silver: | 0 |
| Bronze: | 0 |
| Appearances: | auto |
Saint Lucia competed at the 2019 World Aquatics Championships in Gwangju, South Korea from 12 to 28 July.
See main article: Swimming at the 2019 World Aquatics Championships.
Saint Lucia entered four swimmers.[1]
| Athlete | Event | Heat | Semifinal | Final | ||||
|---|---|---|---|---|---|---|---|---|
| Time | Rank | Time | Rank | Time | Rank | |||
| align=left rowspan=2 | Jayhan Odlum-Smith | 50 m butterfly | 25.47 | 63 | did not advance | |||
| 100 m butterfly | 56.31 | 55 | did not advance | |||||
| align=left rowspan=2 | Jean-Luc Zephir | 50 m freestyle | 23.51 | 64 | did not advance | |||
| 100 m freestyle | 51.65 | =67 | did not advance | |||||
| Athlete | Event | Heat | Semifinal | Final | ||||
|---|---|---|---|---|---|---|---|---|
| Time | Rank | Time | Rank | Time | Rank | |||
| align=left rowspan=2 | Mikaili Charlemagne | 100 m freestyle | 1:00.27 | 65 | did not advance | |||
| 50 m butterfly | 29.24 | 42 | did not advance | |||||
| align=left rowspan=2 | Naima Hazell | 50 m freestyle | 27.85 | =59 | did not advance | |||
| 50 m breaststroke | 34.79 | 42 | did not advance | |||||