Athletics at the 2008 Summer Olympics – Women's 400 metres hurdles Semifinals Semifinals

| Rank_ | Heat | Name_ | Nationality | Result_ |
|---|---|---|---|---|
| 1 | 1 | Sheena Tosta | United States | 54.07 |
| 2 | 2 | Melaine Walker | Jamaica | 54.20 |
| 3 | 1 | Tasha Danvers | Great Britain | 54.31 |
| 4 | 1 | Anna Jesień | Poland | 54.36 |
| 5 | 1 | Ekaterina Bikert | Russia | 54.38 |
| 6 | 2 | Anastasiya Rabchenyuk | Ukraine | 54.60 |
| 7 | 1 | Nickiesha Wilson | Jamaica | 54.67 |
| 8 | 1 | Anastasiya Ott | Russia | 54.74 |
| 9 | 2 | Tiffany Ross-Williams | United States | 54.99 |
| 10 | 2 | Zuzana Hejnová | Czech Republic | 55.17 |
| 11 | 2 | Aïssata Soulama | Burkina Faso | 55.69 |
| 12 | 2 | Irina Obedina | Russia | 55.69 |
| 13 | 2 | Queen Harrison | United States | 55.88 |
| 14 | 2 | Tsvetelina Kirilova | Bulgaria | 55.97 |
| 15 | 1 | Satomi Kubokura | Japan | 56.69 |
| 16 | 1 | Angela Morosanu | Romania | 57.67 |