1985 Japan Open Tennis Championships – Women's singles

Lilian Drescher was the defending champion, but lost in the semifinals to Gabriela Sabatini.

Sabatini won the title by defeating Linda Gates 6–3, 6–4 in the final.

Seeds
• # 🇦🇷 Gabriela Sabatini (champion)

• # 🇺🇸 Beth Herr (second round)

• # Lilian Drescher (semifinals)

• # Mima Jaušovec (first round)

• # Angeliki Kanellopoulou (quarterfinals)

• # 🇵🇪 Laura Gildemeister (semifinals)

• # Andrea Holíková (quarterfinals)

• # Myriam Schropp (quarterfinals)