| Event: | Swimming |
| Games: | 1948 Summer |
| Venue: | Wembley Arena |
| Dates: | 30 July – 7 August 1948 |
| Num Events: | 11 |
| Competitors: | 249 |
| Nations: | 34 |
| Prev: | 1936 |
| Next: | 1952 |
At the 1948 Summer Olympics in London, 11 swimming events were contested, six for men and five for women.[1] All swimming events took place at the Empire Pool. There was a total of 249 participants from 34 countries competing.[2]
| 100 m freestyle | 57.3 (OR) | 57.8 | 58.1 | ||||
| 400 m freestyle | 4:41.0 (OR) | 4:43.4 | 4:47.7 | ||||
| 1500 m freestyle | 19:18.5 | 19:31.3 | 19:43.2 | ||||
| 100 m backstroke | 1:06.4 | 1:06.5 | 1:07.8 | ||||
| 200 m breaststroke | 2:39.3 (OR) | 2:40.2 | 2:43.9 | ||||
| 4 × 200 metre freestyle relay | 8:46.0 (WR) | 8:48.4 | 9:08.0 |
| 100 m freestyle | 1:06.3 | 1:06.5 | 1:07.6 | ||||
| 400 m freestyle | 5:17.8 (OR) | 5:21.2 | 5:22.5 | ||||
| 100 m backstroke | 1:14.4 (OR) | 1:16.0 | 1:16.7 | ||||
| 200 m breaststroke | 2:57.2 | 2:57.7 | 3:00.2 | ||||
| 4 × 100 metre freestyle relay | 4:29.2 (OR) | 4:29.6 | 4:31.6 |
249 swimmers from 34 nations competed.[2]
| width=50 | valign=top | width=50 | valign=top | width=50 | valign=top |