2015 Rakuten Japan Open Tennis Championships – Singles

Kei Nishikori was the defending champion, but lost to Benoît Paire in the semifinals.

Stan Wawrinka won the title, defeating Paire in the final, 6–2, 6–4.

Seeds
• # Stan Wawrinka (champion)

• #🇯🇵 Kei Nishikori (semifinals)

• #🇫🇷 Gilles Simon (quarterfinals)

• #🇫🇷 Richard Gasquet (first round)

• # Kevin Anderson (first round)

• # Marin Čilić (quarterfinals)

• #🇪🇸 Feliciano López (first round)

• #🇧🇬 Grigor Dimitrov (first round)

Seeds
• #🇺🇸 Donald Young (qualified)

• #🇫🇷 Nicolas Mahut (qualifying competition)

• #🇷🇺 Mikhail Youzhny (qualified)

• # Nikoloz Basilashvili (first round)

• #🇫🇷 Pierre-Hugues Herbert (qualifying competition)

• #🇯🇵 Go Soeda (qualifying competition)

• #🇺🇸 Austin Krajicek (qualified)

• #🇯🇵 Yūichi Sugita (first round)

Qualifiers
• # 🇺🇸 Donald Young

• # 🇺🇸 Austin Krajicek

• # 🇷🇺 Mikhail Youzhny

• # 🇦🇺 Matthew Ebden