| Singles | |
|---|---|
| 2020 Shimadzu All Japan Indoor Tennis Championships | |
| Champion |  Xun Fangying |
| Runner-up |  Indy de Vroome |
| Final score | 3–6, 6–3, 7–6(8–6) |
Ylena In-Albon was the defending champion, [1] but chose not to participate.
Xun Fangying won the title, defeating Indy de Vroome in the final, 3–6, 6–3, 7–6(8–6).
Wang Xinyu (Semifinals)
Arina Rodionova (First round) Xun Fangying (Champion) Indy de Vroome (Final)
Kyōka Okamura (Second round) Akiko Omae (Quarterfinals)
Peangtarn Plipuech (First round) Ayano Shimizu (Quarterfinals)| Semifinals | Final | ||||||||||||
| 1 | Wang Xinyu | 6 | 4 | 3 | |||||||||
| 4 | Indy de Vroome | 3 | 6 | 6 | |||||||||
| 4 | Indy de Vroome | 6 | 3 | 66 | |||||||||
| 3 | Xun Fangying | 3 | 6 | 78 | |||||||||
| 3 | Xun Fangying | 6 | 6 | ||||||||||
| Q | Erina Hayashi | 1 | 2 | ||||||||||
| First Round | Second Round | Quarterfinals | Semifinals | ||||||||||||||||||||||||
| 1 | Xin Wang | 6 | 6 | ||||||||||||||||||||||||
| WC | S Oshino | 3 | 2 | 1 | Xin Wang | 6 | 6 | ||||||||||||||||||||
| J Namigata | 4 | 4 | N Hanatani | 1 | 4 | ||||||||||||||||||||||
| N Hanatani | 6 | 6 | 1 | Xin Wang | 4 | 6 | 6 | ||||||||||||||||||||
| M Hontama | 1 | 6 | 6 | 8 | A Shimizu | 6 | 1 | 2 | |||||||||||||||||||
| H Kaji | 6 | 1 | 3 | M Hontama | 7 | 3 | 4 | ||||||||||||||||||||
| WC | M Kato | 4 | 3 | 8 | A Shimizu | 5 | 6 | 6 | |||||||||||||||||||
| 8 | A Shimizu | 6 | 6 | 1 | Xin Wang | 6 | 4 | 3 | |||||||||||||||||||
| 4 | I de Vroome | 6 | 6 | 4 | I de Vroome | 3 | 6 | 6 | |||||||||||||||||||
| Q | K Yoshioka | 1 | 3 | 4 | I de Vroome | 6 | 6 | ||||||||||||||||||||
| Q | Yi Zhang | 6 | 3 | 77 | Q | Yi Zhang | 2 | 4 | |||||||||||||||||||
| E Hozumi | 2 | 6 | 61 | 4 | I de Vroome | 79 | 6 | ||||||||||||||||||||
| N Sato | 3 | 5 | Q | J Kang | 67 | 1 | |||||||||||||||||||||
| Q | J Kang | 6 | 7 | Q | J Kang | 6 | 6 | ||||||||||||||||||||
 T Moore | 77 | 6 | T Moore | 1 | 3 | ||||||||||||||||||||||
| 7 | P Plipuech | 64 | 2 | ||||||||||||||||||||||||
| First Round | Second Round | Quarterfinals | Semifinals | ||||||||||||||||||||||||
| 6 | A Omae | 6 | 6 | ||||||||||||||||||||||||
| M Kobori | 2 | 1 | 6 | A Omae | 6 | 6 | |||||||||||||||||||||
| M Uchijima | 64 | 6 | 77 | M Uchijima | 1 | 2 | |||||||||||||||||||||
| M Imanishi | 77 | 3 | 63 | 6 | A Omae | 3 | 7 | 5 | |||||||||||||||||||
| Q | C Hosonuma | 6 | 6 | 3 | F Xun | 6 | 5 | 7 | |||||||||||||||||||
| M Ayukawa | 3 | 4 | Q | C Hosonuma | 2 | 4 | |||||||||||||||||||||
 E Bektas | 4 | 3 | 3 | F Xun | 6 | 6 | |||||||||||||||||||||
| 3 | F Xun | 6 | 6 | 3 | F Xun | 6 | 6 | ||||||||||||||||||||
| 5 | K Okamura | 6 | 6 | Q | E Hayashi | 1 | 2 | ||||||||||||||||||||
| H Kuwata | 1 | 3 | 5 | K Okamura | 1 | 6 | 4 | ||||||||||||||||||||
| H Arakawa | 6 | 2 | 63 | Q | E Hayashi | 6 | 4 | 6 | |||||||||||||||||||
| Q | E Hayashi | 2 | 6 | 77 | Q | E Hayashi | 6 | 6 | |||||||||||||||||||
| Q | A Matsumoto | 5 | 2 | R Ushijima | 0 | 2 | |||||||||||||||||||||
| M Yamaguchi | 7 | 6 | M Yamaguchi | 6 | 65 | 2 | |||||||||||||||||||||
| R Ushijima | 6 | 1 | 77 | R Ushijima | 2 | 77 | 6 | ||||||||||||||||||||
| 2 | Ar Rodionova | 4 | 6 | 63 | |||||||||||||||||||||||
An-Sophie Mestach was the defending champion, but she withdrew before the tournament began.
Taylor Townsend was the defending champion, having won the event in 2012, but chose not to defend her title.
Simona Halep won the first edition of the tournament, defeating Roberta Vinci in the final, 6–1, 6–3.
Samantha Stosur successfully defended her title, defeating Zarina Diyas in the final, 7–6(9–7), 6–3.
Jelena Janković was the defending champion, but lost in the final to Lesia Tsurenko 4–6, 6–3, 4–6.
Xun Fangying and You Xiaodi were the defending champions, but both players chose not to participate.
Zhang Kailin was the defending champion, but lost in the first round to Xun Fangying.
Duan Yingying was the defending champion, but lost in the first round to Arina Rodionova.
Lesia Tsurenko was the defending champion, but lost in the first round to Aleksandra Krunić.
Wang Qiang was the defending champion, but chose not to participate.
Han Xinyun and Zhu Lin were the defending champions, but chose not to participate together. Han partnered Vera Zvonareva, but lost in the semifinals to Duan Yingying and Wang Yafan. Zhu played alongside You Xiaodi, but lost in the first round to Prarthana Thombare and Xun Fangying.
Peng Shuai was the defending champion, but withdrew before the tournament began.
Zhang Shuai was the defending champion, but she withdrew before her first round match against Wang Yafan.
Maria Sharapova was the defending champion, but withdrew due to a shoulder injury.
Belinda Bencic was the defending champion, but chose to compete in Houston instead.
This was the first edition of the women's tournament.
Wang Qiang was the defending champion, but lost in the first round to Peng Shuai.
Dayana Yastremska was the defending champion, but withdrew before the tournament began.
World No. 1 Ashleigh Barty defeated Aryna Sabalenka in the final, 3–6, 6–0, 6–3 to win the Women's Singles tennis title at the 2021 edition of the Stuttgart Open.
Jeļena Ostapenko was the defending champion, having won the previous edition in 2019, but lost to Clara Tauson in the final, 3–6, 6–4, 4–6.