Athletics at the 2008 Summer Olympics – Men's 400 metres Heat 5 Heat 5

| Rank_ | Lane | Athlete | Nationality | Time_ | React |
|---|---|---|---|---|---|
| 1 | 2 | LaShawn Merritt | United States | 44.96 | 0.214 |
| 2 | 7 | Saul Weigopwa | Nigeria | 45.19 | 0.172 |
| 3 | 8 | Claudio Licciardello | Italy | 45.25 | 0.186 |
| 4 | 3 | Jonathan Borlée | Belgium | 45.25 | 0.225 |
| 5 | 6 | Ato Modibo | Trinidad and Tobago | 45.63 | 0.195 |
| 6 | 9 | Alleyne Francique | Grenada | 46.15 | 0.215 |
| 7 | 5 | Geiner Mosquera | Colombia | 46.59 | 0.268 |
| 8 | 4 | Siraj Williams | Liberia | 47.89 | 0.288 |