2018 Japan Women's Open

The 2018 Japan Women's Open was a women's tennis tournament played on outdoor hard courts. It was the tenth edition of the Japan Women's Open, and part of the WTA International tournaments of the 2018 WTA Tour. It was held at the Regional Park Tennis Stadium in Hiroshima, Japan, from September 10 through September 16, 2018. This is the first year that the tournament was held in Hiroshima.

Prize money
1 Qualifiers prize money is also the Round of 32 prize money 2 Per team

Seeds

 * Rankings are as of August 27, 2018

Other entrants
The following players received wildcards into the singles main draw:
 * 🇯🇵 Misaki Doi
 * 🇯🇵 Nao Hibino
 * 🇯🇵 Miyu Kato

The following player entered the singles main draw with a protected ranking:
 * 🇱🇺 Mandy Minella

The following players received entry from the qualifying draw:
 * 🇺🇸 Amanda Anisimova
 * 🇦🇺 Priscilla Hon
 * 🇦🇺 Arina Rodionova
 * 🇨🇳 Zhang Yuxuan

Withdrawals

 * Before the tournament
 * 🇷🇴 Ana Bogdan → replaced by 🇫🇷 Fiona Ferro
 * 🇺🇸 Jennifer Brady → replaced by Jana Fett
 * 🇧🇾 Aliaksandra Sasnovich → replaced by 🇨🇳 Duan Yingying
 * Stefanie Vögele → replaced by 🇵🇱 Magdalena Fręch

Retirements

 * 🇰🇿 Yulia Putintseva (lower back injury)

Seeds

 * 1 Rankings are as of August 27, 2018

Other entrants
The following pairs received wildcards into the doubles main draw:
 * 🇯🇵 Miharu Imanishi / 🇵🇱 Alicja Rosolska
 * 🇯🇵 Hiroko Kuwata / 🇯🇵 Chihiro Muramatsu

Withdrawals

 * During the tournament
 * 🇦🇺 Priscilla Hon (gastrointestinal illness)

Singles

 * Hsieh Su-wei def. 🇺🇸 Amanda Anisimova 6–2, 6–2

Doubles

 * 🇯🇵 Eri Hozumi / 🇨🇳 Zhang Shuai def. 🇯🇵 Miyu Kato / 🇯🇵 Makoto Ninomiya 6–2, 6–4