| Singles | |
|---|---|
| 2017 Japan Women's Open | |
| Champion |  Zarina Diyas |
| Runner-up |  Miyu Kato |
| Final score | 6–2, 7–5 |
Christina McHale was the defending champion, but lost in the semifinals to Zarina Diyas.
Qualifier Diyas went on to win her first WTA title, defeating another qualifier Miyu Kato in the final, 6–2, 7–5.
Former world no. 4 Kimiko Date played her last professional match at this tournament, losing in straight sets to Aleksandra Krunić in the first round.
Kristina Mladenovic (first round)
Zhang Shuai (second round)
Elise Mertens (quarterfinals)
Kristýna Plíšková (second round)
Samantha Stosur (first round) Naomi Osaka (first round)
Alison Riske (second round) Yulia Putintseva (quarterfinals)| Semifinals | Final | ||||||||||||
| Q |  Jana Fett | 6 | 61 | 4 | |||||||||
| Q | Miyu Kato | 4 | 77 | 6 | |||||||||
| Q | Miyu Kato | 2 | 5 | ||||||||||
| Q | Zarina Diyas | 6 | 7 | ||||||||||
| Christina McHale | 4 | 6 | 3 | ||||||||||
| Q | Zarina Diyas | 6 | 0 | 6 | |||||||||
| First round | Second round | Quarterfinals | Semifinals | ||||||||||||||||||||||||
| 1/WC | K Mladenovic | 3 | 4 | ||||||||||||||||||||||||
| Q | J Fett | 6 | 6 | Q | J Fett | 6 | 6 | ||||||||||||||||||||
 A Sasnovich | 3 | 0r |  J Čepelová | 0 | 3 | ||||||||||||||||||||||
| J Čepelová | 6 | 1 | Q | J Fett | 6 | 4 | 6 | ||||||||||||||||||||
 S-w Hsieh | 5 | 2 | Q Wang | 3 | 6 | 3 | |||||||||||||||||||||
| Q Wang | 7 | 6 | Q Wang | 6 | 6 | ||||||||||||||||||||||
| K Nara | 6 | 6 | K Nara | 2 | 3 | ||||||||||||||||||||||
| 6 | N Osaka | 3 | 0 | Q | J Fett | 6 | 61 | 4 | |||||||||||||||||||
| 4/WC | Kr Plíšková | 7 | 7 | Q | M Kato | 4 | 77 | 6 | |||||||||||||||||||
| K-c Chang | 5 | 5 | 4/WC | Kr Plíšková | 5 | 3 | |||||||||||||||||||||
| Q | M Kato | 6 | 6 | Q | M Kato | 7 | 6 | ||||||||||||||||||||
| N Hibino | 3 | 4 | Q | M Kato | 6 | 6 | |||||||||||||||||||||
 A Krunić | 6 | 6 | A Krunić | 1 | 3 | ||||||||||||||||||||||
| WC | K Date | 0 | 0 | A Krunić | 6 | 6 | |||||||||||||||||||||
| M Brengle | 7 | 3 | 4 | 7 | A Riske | 3 | 4 | ||||||||||||||||||||
| 7 | A Riske | 5 | 6 | 6 | |||||||||||||||||||||||
| First round | Second round | Quarterfinals | Semifinals | ||||||||||||||||||||||||
| 5 | S Stosur | 6 | 5 | 1 | |||||||||||||||||||||||
 S Sorribes Tormo | 3 | 7 | 6 | S Sorribes Tormo | 1 | 1 | |||||||||||||||||||||
| C McHale | 6 | 6 | C McHale | 6 | 6 | ||||||||||||||||||||||
| Q |  D Kovinić | 2 | 4 | C McHale | 6 | 6 | |||||||||||||||||||||
| R Ozaki | 1 | 5 | 3 | E Mertens | 4 | 1 | |||||||||||||||||||||
 M Linette | 6 | 7 | M Linette | 1 | 5 | ||||||||||||||||||||||
 E Rodina | 66 | 1 | 3 | E Mertens | 6 | 7 | |||||||||||||||||||||
| 3 | E Mertens | 78 | 6 | C McHale | 4 | 6 | 3 | ||||||||||||||||||||
| 8 | Y Putintseva | 6 | 4 | 6 | Q | Z Diyas | 6 | 0 | 6 | ||||||||||||||||||
| Y Duan | 4 | 6 | 4 | 8 | Y Putintseva | 6 | 2 | ||||||||||||||||||||
| PR | M Eguchi | 5 | 2 | X Han | 2 | 0r | |||||||||||||||||||||
| X Han | 7 | 6 | 8 | Y Putintseva | 6 | 1 | 3 | ||||||||||||||||||||
| Q | Z Diyas | 3 | 6 | 6 | Q | Z Diyas | 4 | 6 | 6 | ||||||||||||||||||
| M Doi | 6 | 1 | 1 | Q | Z Diyas | 6 | 6 | ||||||||||||||||||||
 R Hogenkamp | 3 | 3 | 2 | S Zhang | 4 | 2 | |||||||||||||||||||||
| 2 | S Zhang | 6 | 6 | ||||||||||||||||||||||||
Danka Kovinić (qualified) Zarina Diyas (qualified) Kristie Ahn (first round) Jana Fett (qualified) Arina Rodionova (second round)
Jang Su-jeong (second round) Arantxa Rus (first round) Quirine Lemoine (second round)| First round | Second round | Qualifying competition | ||||||||||||||||||
| 1 | Danka Kovinić | 3 | 6 | 6 | ||||||||||||||||
| Jennifer Elie | 6 | 4 | 3 | |||||||||||||||||
| 1 | Danka Kovinić | 2 | 6 | 6 | ||||||||||||||||
| Alt | Erika Sema | 6 | 3 | 2 | ||||||||||||||||
| WC | Moyuka Uchijima | 6 | 4 | 2 | ||||||||||||||||
| Alt | Erika Sema | 3 | 6 | 6 | ||||||||||||||||
| 1 | Danka Kovinić | 6 | 3 | 6 | ||||||||||||||||
| Miharu Imanishi | 3 | 6 | 2 | |||||||||||||||||
 İpek Soylu | 2 | 1 | ||||||||||||||||||
| Miharu Imanishi | 6 | 6 | ||||||||||||||||||
| Miharu Imanishi | 2 | 6 | 6 | |||||||||||||||||
| Lizette Cabrera | 6 | 4 | 0 | |||||||||||||||||
| Lizette Cabrera | 6 | 4 | 6 | |||||||||||||||||
| 7 | Arantxa Rus | 2 | 6 | 3 | ||||||||||||||||
| First round | Second round | Qualifying competition | ||||||||||||||||||
| 2 | Zarina Diyas | 6 | 6 | |||||||||||||||||
| Danielle Collins | 3 | 2 | ||||||||||||||||||
| 2 | Zarina Diyas | 6 | 6 | |||||||||||||||||
 Giulia Gatto-Monticone | 3 | 2 | ||||||||||||||||||
| Ayano Shimizu | 2 | 4 | ||||||||||||||||||
| Giulia Gatto-Monticone | 6 | 6 | ||||||||||||||||||
| 2 | Zarina Diyas | 1 | 77 | 6 | ||||||||||||||||
 Luksika Kumkhum | 6 | 64 | 4 | |||||||||||||||||
| Mayo Hibi | 2 | 6 | 4 | |||||||||||||||||
| Luksika Kumkhum | 6 | 3 | 6 | |||||||||||||||||
| Luksika Kumkhum | 6 | 6 | ||||||||||||||||||
| 6 | Jang Su-jeong | 4 | 4 | |||||||||||||||||
| WC | Himari Sato | 1 | 2 | |||||||||||||||||
| 6 | Jang Su-jeong | 6 | 6 | |||||||||||||||||
| First round | Second round | Qualifying competition | ||||||||||||||||||
| 3 | Kristie Ahn | 61 | 6 | 4 | ||||||||||||||||
| Miyu Kato | 77 | 4 | 6 | |||||||||||||||||
| Miyu Kato | 6 | 6 | ||||||||||||||||||
| Başak Eraydın | 3 | 0 | ||||||||||||||||||
| Başak Eraydın | 4 | 77 | 6 | |||||||||||||||||
| Riko Sawayanagi | 6 | 64 | 3 | |||||||||||||||||
| Miyu Kato | 6 | 2 | 77 | |||||||||||||||||
| Magdalena Fręch | 3 | 6 | 63 | |||||||||||||||||
 Rebecca Peterson | 6 | 5 | 2 | |||||||||||||||||
| Magdalena Fręch | 3 | 7 | 6 | |||||||||||||||||
| Magdalena Fręch | 4 | 77 | 6 | |||||||||||||||||
| 5 | Arina Rodionova | 6 | 63 | 1 | ||||||||||||||||
| WC | Mari Osaka | 6 | 4 | 4 | ||||||||||||||||
| 5 | Arina Rodionova | 4 | 6 | 6 | ||||||||||||||||
| First round | Second round | Qualifying competition | ||||||||||||||||||
| 4 | Jana Fett | 6 | 6 | |||||||||||||||||
| Eri Hozumi | 2 | 2 | ||||||||||||||||||
| 4 | Jana Fett | 6 | 4 | 6 | ||||||||||||||||
| Karolína Muchová | 1 | 6 | 4 | |||||||||||||||||
| Hiroko Kuwata | 4 | 2 | ||||||||||||||||||
| Karolína Muchová | 6 | 6 | ||||||||||||||||||
| 4 | Jana Fett | 6 | 6 | |||||||||||||||||
| Lesley Kerkhove | 4 | 0 | ||||||||||||||||||
| Junri Namigata | 2 | 1 | ||||||||||||||||||
| Lesley Kerkhove | 6 | 6 | ||||||||||||||||||
| Lesley Kerkhove | 6 | 7 | ||||||||||||||||||
| 8 | Quirine Lemoine | 3 | 5 | |||||||||||||||||
| Peangtarn Plipuech | 1 | 5 | ||||||||||||||||||
| 8 | Quirine Lemoine | 6 | 7 | |||||||||||||||||
Slovak pair Jana Čepelová and Chantal Škamlová were the defending champions. They defeated Tímea Babos and Gabriela Dabrowski in the 2010 final, but chose to not start this year.
Tímea Babos and Sloane Stephens were the defending champions, but they chose to not participate this year.
Serena Williams was the two-time defending champion, but lost in the second round to Jana Čepelová, ending her 15-match winning streak at this tournament, and her 28-match winning streak on clay.
Elina Svitolina was the defending champion, and successfully defended her title, defeating Bojana Jovanovski in the final 6–1, 7–6(7–2).
Andrea Petkovic was the defending champion, but she lost to Angelique Kerber in the semifinals.
Danka Kovinić was the defending champion, but she lost in the first round to Tessah Andrianjafitrimo.
This was the first edition of the tournament.
Danka Kovinić was the defending champion, but chose to participate in Rome instead.
The 2017 Japan Women's Open was a women's tennis tournament played on outdoor hard courts. It was the ninth edition of the Japan Women's Open, and part of the WTA International tournaments of the 2017 WTA Tour. It was held at the Ariake Coliseum in Tokyo, Japan, from September 11 through September 17, 2017.
Johanna Konta was the defending champion after winning the last event in 2015, but chose to participate in Cincinnati instead.
Kristýna Plíšková was the defending champion, but chose not to participate.
Caroline Wozniacki was the defending champion and successfully defended her title, defeating Anastasia Pavlyuchenkova in the final, 6–0, 7–5. This marked Wozniacki's first title of 2017 and snapped a six-match losing streak in tournament finals.
Karolína Plíšková was the defending champion, but lost in the third round to Catherine Bellis.
Denisa Allertová was the defending champion, but lost to Vitalia Diatchenko in the first round.
Anastasia Pavlyuchenkova was the defending champion, but chose not to participate.
Zarina Diyas was the defending champion, but lost in the quarterfinals to Zhang Shuai.
Caroline Wozniacki was the two-time defending champion, but lost in the second round to Camila Giorgi.
Madison Keys was the defending champion but lost in the second round to Ons Jabeur.
Simona Halep won her first Italian Open title, after the defending champion Karolína Plíšková retired from the final, with the scoreline at 6–0, 2–1.
Aryna Sabalenka defeated Ashleigh Barty in the final, 6–0, 3–6, 6–4, to win the women's singles tennis title at the 2021 Madrid Open. It was Sabalenka's 10th career WTA Tour singles title and her first title on clay.