(D)：Difending Champion
| Date | Championships | Course | Venue | Champion | |
| 4/25 – 4/28 | Asia Golf Circuit Dunlop Open Golf Championship | Ibaraki Golf Club West Course | IBARAKI | Roger Mackay | |
| 6/4 – 6/6 | 33rd 1991 Japan Women’s Amateur Golf Championship | Gifu Country Club | GIFU | Miki Saito | |
| 6/27 – 6/30 |  |
24th 1991 Japan Women’s Open Golf Championship | Sapporo Golf Club Wattsu Course | HOKKAIDO | Ai-Yu Tu |
| 7/16 – 7/19 | 76th 1991 Japan Amateur Golf Championship | Tsukuba Country Club | IBARAKI | Katsumasa Miyamoto | |
| 8/7 – 8/9 | 1991 Japan Junior Golf Championship High School Boys | Kasumigaseki Country Club West Course | SAITAMA | Tetsuya Haraguchi | |
| 8/8 – 8/9 | 1991 Japan Junior Golf Championship Middle School Boys | Kasumigaseki Country Club West Course | SAITAMA | Kentaro Yonekura | |
| 8/8 – 8/9 | 1991 Japan Junior Golf Championship Girls | Kasumigaseki Country Club West Course | SAITAMA | Akiko Fukushima | |
| 8/21 – 8/23 | 45th 1991 Japan Collegiate Golf Championship | Haga Country Club South/West Course | TOCHIGI | Shigeki Maruyama | |
| 8/21 – 8/23 | 28th 1991 Japan Women’s Collegiate Golf Championship | Haga Country Club South/West Course | TOCHIGI | Yukiyo Haga | |
| 10/10 – 10/13 | |
56th 1991 Japan Open Golf Championship | Shimonoseki Golf Club | YAMAGUCHI | Tsuneyuki Nakajima |
| 10/17 – 10/18 | 13th 1991 Japan Senior Golf Championship | Onahama Country Club South/West Course | FUKUSHIMA | Kinji Ando | |
| 10/24 – 10/27 | |
1st 1991 Japan Senior Open Golf Championship | Hatoyama Country Club | SAITAMA | Seiichi Kanai |