See main article: Swimming at the 2007 Pan American Games.
The Men's 400m Freestyle event at the 2007 Pan American Games occurred at the Maria Lenk Aquatic Park in Rio de Janeiro, Brazil on 17 and 18 July. A total of 17 swimmers initially swam the race.
| Rank | Swimmer | Semifinals | Final | |
|---|---|---|---|---|
| Time | Rank | Time | ||
| 1 | 3:53.30 | 3 | 3:49.77 | |
| 2 | 3:51.32 | 1 | 3:50.62 | |
| 3 | 3:51.47 | 2 | 3:51.18 | |
| 4 | 3:57.34 | 5 | 3:55.93 | |
| 5 | 3:57.64 | 6 | 3:57.51 | |
| 6 | 3:57.25 | 4 | 3:59.53 | |
| 7 | 4:00.36 | 8 | 3:59.66 | |
| 8 | 3:59.97 | 7 | 4:02.91 | |
| 9 | 4:00.37 | |||
| 10 | 4:00.76 | |||
| 11 | 4:01.63 | |||
| 12 | 4:02.01 | |||
| 13 | 4:02.37 | |||
| 14 | 4:06.37 | |||
| 15 | 4:07.14 | |||
| 16 | 4:07.47 | |||
| 17 | 4:12.68 | |||