1991 Tokyo Indoor – Singles

Ivan Lendl was the defending champion, but lost in the semifinals this year.

Stefan Edberg won the title, defeating Derrick Rostagno in the final, 6–3, 1–6, 6–2.

Seeds
• # 🇸🇪 Stefan Edberg (champion)

• # 🇩🇪 Boris Becker (quarterfinals)

• # Ivan Lendl (semifinals)

• # 🇺🇸 Andre Agassi (quarterfinals)

• # 🇺🇸 David Wheaton (quarterfinals)

• # Goran Ivanišević (semifinals)

• # 🇺🇸 Derrick Rostagno (final)

• # 🇺🇸 Michael Chang (quarterfinals)

• # Andrei Chesnokov (third round)

• # 🇺🇸 Richey Reneberg (third round)

• # 🇦🇺 Todd Woodbridge (second round)

• # 🇺🇸 MaliVai Washington (third round)

• # 🇦🇺 Wally Masur (third round)

• # Wayne Ferreira (second round)

• # 🇫🇷 Frédéric Fontang (third round)

• # 🇯🇵 Shuzo Matsuoka (third round)