| Men's Singles | |
|---|---|
| 2005 AIG Japan Open Tennis Championships | |
| Champion |
|
| Runner-up |
|
| Final score | 1–6, 7–6(9–7), 6–4 |
Jiří Novák was the defending champion, but did not participate.
Wesley Moodie won the title, defeating Mario Ančić in the final 1–6, 7–6(9–7), 6–4.
All seeds receive a bye into the second round.