| 2004 AIG Japan Open Tennis Championships | |
|---|---|
| Date | 4–10 October |
| Edition | 31st |
| Surface | Hard / outdoors |
| Location | Tokyo, Japan |
| Venue | Ariake Coliseum |
| Champions | |
| Men's singles | |
 Jiří Novák[1] | |
| Women's singles | |
 Maria Sharapova | |
| Men's doubles | |
 Jared Palmer / Pavel Vízner[2] | |
| Women's doubles | |
 Shinobu Asagoe /  Katarina Srebotnik | |
The 2004 AIG Japan Open Tennis Championships was a combined men's and women's tennis tournament played on outdoor hard courts at the Ariake Coliseum in Tokyo in Japan. The men's tournament was part of the International Series Gold of the 2004 ATP Tour and the women's tournament was part of the Tier III category of the 2004 WTA Tour. It was the 31st edition of the event and was held from 4 October through 10 October 2004. Jiří Novák and Maria Sharapova won the singles titles.
- ^ "2004 Tokyo Men's Singles draw". www.atpworldtour.com. Association of Tennis Professionals (ATP).
- ^ "2004 Tokyo Men's Doubles draw". www.atpworldtour.com. Association of Tennis Professionals (ATP).