(D)：Difending Champion
| Date | Championships | Course | Venue | Champion | |
| 6/24 – 6/28 | 45th 2003 Japan Women’s Amateur Golf Championship | Kuwana Country Club | MIE | Ai Miyazato | |
| 7/8 – 7/12 | 88th 2003 Japan Amateur Golf Championship | Akita Tsubakidai Country Club Tsubaki/Satsuki Course | AKITA | Shintaro Kai | |
| 8/20 – 8/22 | 9th 2003 Japan Junior Golf Championship Boy’s 15-17 Division | Kasumigaseki Country Club East Course | SAITAMA | Yuta Ikeda | |
| 8/21 – 8/22 | 9th 2003 Japan Junior Golf Championship Boy’s 12-14 Division | Kasumigaseki Country Club West Course | SAITAMA | Yusaku Matsuoka | |
| 8/21 – 8/22 | 9th 2003 Japan Junior Golf Championship Girl’s 15-17 Division | Kasumigaseki Country Club West Course | SAITAMA | Ai Miyazato | |
| 8/21 – 8/22 | 9th 2003 Japan Junior Golf Championship Girl’s 12-14 Division | Kasumigaseki Country Club West Course | SAITAMA | Maiko Wakabayashi | |
| 8/26 – 8/29 | 57th 2003 Japan Collegiate Golf Championship | Central Golf Club East Course | IBARAKI | Shintaro Kai | |
| 8/27 – 8/29 | 40th 2003 Japan Women’s Collegiate Golf Championship | Central Golf Club East Course | IBARAKI | Mao Koyama | |
| 10/2 – 10/5 |  |
36th 2003 Japan Women’s Open Golf Championship | Chiba Country Club Noda Course | CHIBA | Michiko Hattori |
| 10/16 – 10/19 | |
68th 2003 Japan Open Golf Championship | Nikko Country Club | TOCHIGI | Keiichiro Fukabori |
| 10/23 – 10/26 | |
13th 2003 Japan Senior Open Golf Championship | Takarazuka Golf Club New Course | HYOGO | Katsunari Takahashi |
| 11/5 – 11/7 | 11th 2003 Japan Women’s Senior Golf Championship | Biwako Country Club Ritto/Mikami Course | SHIGA | Yukiko Oita | |
| 11/11 – 11/14 | 8th 2003 Japan Mid-Amateur Golf Championship | Nanzan Country Club | AICHI | Naoyuki Tamura | |
| 11/12 – 11/14 | 8th 2003 Japan Women’s Mid-Amateur Golf Championship | Dazaifu Golf Club | FUKUOKA | Itsuko Miki | |
| 11/17 – 11/18 | 10th 2003 Japan Mid-Senior Golf Championship | Hanno Golf Club | SAITAMA | Hideya Yamamoto | |
| 11/17 – 11/18 | 10th 2003 Japan Grand-Senior Golf Championship | Hanno Golf Club | SAITAMA | Kisaburo Ando | |
| 11/19 – 11/21 | 25th 2003 Japan Senior Golf Championship | Hakone Country Club | KANAGAWA | Toshio Shirai | |