Swimming at the 2007 World Aquatics Championships – Men's 100 metre freestyle Semifinals Semifinals

| Rank_ | Heat | Lane | Name_ | Nationality | Time_ |
|---|---|---|---|---|---|
| 1 | 2 | 4 | Jason Lezak | United States | 48.51 |
| 2 | 1 | 4 | Filippo Magnini | Italy | 48.60 |
| 3 | 2 | 5 | Pieter van den Hoogenband | Netherlands | 48.72 |
| 4 | 2 | 3 | Brent Hayden | Canada | 48.79 |
| 5 | 2 | 6 | Eamon Sullivan | Australia | 48.86 |
| 6 | 1 | 6 | Ryk Neethling | South Africa | 48.87 |
| 6 | 2 | 2 | César Cielo Filho | Brazil | 48.87 |
| 6 | 2 | 8 | Roland Schoeman | South Africa | 48.87 |
| 9 | 1 | 5 | Alain Bernard | France | 48.89 |
| 10 | 1 | 2 | Stefan Nystrand | Sweden | 48.92 |
| 11 | 2 | 7 | Albert Subirats Altes | Venezuela | 49.17 |
| 12 | 1 | 3 | Simon Burnett | Great Britain | 49.22 |
| 13 | 1 | 7 | Dominik Meichtry | Switzerland | 49.27 |