1989 Suntory Japan Open Tennis Championships – Women's singles

Patty Fendick was the defending champion but did not compete that year.

Kumiko Okamoto won in the final 6–4, 6–2 against Elizabeth Smylie.

Seeds
A champion seed is indicated in bold text while text in italics indicates the round in which that seed was eliminated.


 * 1) 🇦🇺 Anne Minter (semifinals)
 * 2) 🇳🇿 Belinda Cordwell (semifinals)
 * 3) 🇺🇸 Ann Henricksson (second round)
 * 4) 🇧🇪 Sandra Wasserman (quarterfinals)
 * 5) 🇯🇵 Etsuko Inoue (quarterfinals)
 * 6) 🇺🇸 Betsy Nagelsen (quarterfinals)
 * 7) 🇬🇧 Monique Javer (second round)
 * 8) 🇺🇸 Louise Allen (first round)