2019 Japan Women's Open – Singles

Hsieh Su-wei was the defending champion, but lost to Nao Hibino in the quarterfinals.

Hibino went on to win the title, defeating Misaki Doi in the final, 6–3, 6–2.

Seeds
• # Hsieh Su-wei (quarterfinals)

• #🇷🇺 Veronika Kudermetova (semifinals)

• #🇧🇪 Alison Van Uytvanck (quarterfinals)

• #🇷🇺 Anastasia Potapova (first round)

• #🇩🇪 Tatjana Maria (first round)

• #🇰🇿 Zarina Diyas (second round, retired)

• #🇪🇸 Sara Sorribes Tormo (quarterfinals)

• #🇩🇪 Laura Siegemund (quarterfinals)

Seeds
• # 🇷🇴 Patricia Maria Țig (qualified)

• # 🇰🇷 Han Na-lae (qualifying competition)

• # 🇦🇺 Zoe Hives (qualified)

• # 🇧🇬 Viktoriya Tomova (qualified)

• # 🇷🇺 Valeria Savinykh (qualified)

• # 🇦🇺 Destanee Aiava (first round)

• # 🇯🇵 Mayo Hibi (qualifying competition)

• # 🇪🇸 Georgina García Pérez (first round)

• # 🇨🇦 Leylah Annie Fernandez (qualified)

• # 🇯🇵 Yuki Naito (first round)

• # 🇰🇷 Jang Su-jeong (qualifying competition)

• # 🇯🇵 Miharu Imanishi (qualifying competition)

Qualifiers
• # 🇷🇴 Patricia Maria Țig

• # 🇨🇦 Leylah Annie Fernandez

• # 🇦🇺 Zoe Hives

• # 🇧🇬 Viktoriya Tomova

• # 🇷🇺 Valeria Savinykh

• # 🇯🇵 Junri Namigata