| Japan Women's Open Tennis | |
| City: | Osaka (2009–2014, 2023-) Tokyo (2015–2017) Hiroshima (2018–2019) |
| Country: | Japan |
| Founded: | 2009 |
| Editions: | 11 (2019) |
| Venue: | Utsubo Tennis Center (2009-2014, 2023-) Ariake Tennis Forest Park (2015-2017) Regional Park Tennis Stadium (2018-2019) |
| Surface: | Hard / outdoors |
| Website: | jta-tennis.or.jp |
| Singles: |  Ashlyn Krueger |
| Wta Tier: | International (2009-2019) WTA 250 (2023–current) |
| Wta Draw: | 32 / 24 / 16 |
| Wta Prize Money: | (2023) |
The Japan Women's Open Tennis is a professional women's tennis tournament played on outdoor hard courts. The event is affiliated with the Women's Tennis Association (WTA), and is an International-level tournament on the WTA Tour. As successor to the Japan Open (where men and women played simultaneously, up to 2008) the event was held in women-only form for the first time in 2009, and was the second tournament of the season held in Japan: the Pan Pacific Open, a Premier 5 tournament, was held two weeks before. In 2015, the event was moved from Osaka to Tokyo and in 2018 to Hiroshima, before returning to Osaka in 2023 after a three year hiatus.
| Location | Year | Champion | Runner-up | Score |
|---|---|---|---|---|
| Osaka | 6–3, 7–6(8–6) | |||
| 2022 | no competition (due to financial crisis) | |||
| 2021 | no competition (due to COVID-19 pandemic)[1] [2] | |||
| 2020 | ||||
| Hiroshima | 6–3, 6–2 | |||
| 6–2, 6–2 | ||||
| Tokyo | 6–2, 7–5 | |||
| 3–6, 6–4, 6–4 | ||||
| 4–6, 6–3, 6–3 | ||||
| Osaka |  Samantha Stosur (3) | 7–6(9–7), 6–3 | ||
| Samantha Stosur (2) | 3–6, 7–5, 6–2 | |||
| 7–5, 5–7, 7–6(7–4) | ||||
| 6–3, 6–1 | ||||
 Tamarine Tanasugarn | 7–5, 6–7(7–4), 6–1 | |||
| 7–5, 6–1 | ||||
| Location | Year | Champions | Runners-up | Score |
|---|---|---|---|---|
| Osaka | 7–6(7–3), 6–3 | |||
| 2022 | no competition (due to financial crisis) | |||
| 2021 | no competition (due to COVID-19 pandemic) | |||
| 2020 | ||||
| Hiroshima | 3–6, 6–4, [10–4] | |||
 Eri Hozumi  Zhang Shuai (2) | 6–2, 6–4 | |||
| Tokyo | 6–0, 2–6, [10–5] | |||
| Shuko Aoyama (2) Makoto Ninomiya |  Jocelyn Rae Anna Smith | 6–3, 6–3 | ||
| 6–1, 6–2 | ||||
| Osaka | 6–1, 6–2 | |||
| 6–4, 6–3 | ||||
| 6–1, 6–4 | ||||
| 7–5, 3–6, [11–9] | ||||
| 6–0, 6–3 | ||||
| 6–2, 6–4 | ||||