Swimming at the 2008 Summer Olympics – Women's 100 metre freestyle Semifinal 1 Semifinal 1

| Rank_ | Lane | Name_ | Nationality | Time_ |
|---|---|---|---|---|
| 1 | 5 | Natalie Coughlin | United States | 53.70 |
| 2 | 6 | Zhu Yingwen | China | 53.84 |
| 3 | 4 | Britta Steffen | Germany | 53.96 |
| 4 | 3 | Lisbeth Trickett | Australia | 54.10 |
| 5 | 2 | Josefin Lillhage | Sweden | 54.59 |
| 6 | 1 | Lacey Nymeyer | United States | 54.74 |
| 7 | 8 | Petra Dallmann | Germany | 55.05 |
| 8 | 7 | Aliaksandra Herasimenia | Belarus | 55.31 |