Swimming at the 2000 Summer Olympics – Men's 100 metre butterfly Semifinal 1 Semifinal 1

| Rank_ | Lane | Name_ | Nationality | Time_ |
|---|---|---|---|---|
| 1 | 4 | Geoff Huegill | Australia | 51.96 |
| 2 | 5 | Takashi Yamamoto | Japan | 53.10 |
| 3 | 1 | Joris Keizer | Netherlands | 53.33 |
| 4 | 3 | Zsolt Gáspár | Hungary | 53.45 |
| 5 | 6 | Denys Sylantyev | Ukraine | 53.51 |
| 6 | 2 | James Hickman | Great Britain | 53.55 |
| 7 | 7 | Tommy Hannan | United States | 53.59 |
| 8 | 8 | Stefan Aartsen | Netherlands | 53.81 |