2022 Keio Challenger – Men's singles

Kwon Soon-woo was the defending champion but chose not to defend his title.

Christopher O'Connell won the title after defeating Yosuke Watanuki 6–1, 6–7(5–7), 6–3 in the final.

Seeds
• # 🇦🇺 Christopher O'Connell (champion)

• # 🇦🇺 John Millman (quarterfinals, withdrew)

• # 🇯🇵 Kaichi Uchida (quarterfinals)

• # 🇧🇦 Damir Džumhur (quarterfinals)

• # Wu Tung-lin (quarterfinals)

• # 🇯🇵 Hiroki Moriya (first round)

• # 🇯🇵 Yosuke Watanuki (final)

• # 🇨🇿 Zdeněk Kolář (first round)