2020 Bangkok Challenger II – Singles

James Duckworth was the defending champion but chose not to defend his title.

Federico Gaio won the title after Robin Haase retired in the final trailing 1–6, 6–4, 2–4 in the third set.

Seeds
All seeds receive a bye into the second round. • # 🇨🇿 Jiří Veselý (quarterfinals)

• # 🇯🇵 Go Soeda (third round)

• # 🇮🇹 Paolo Lorenzi (second round)

• # 🇫🇷 Antoine Hoang (second round)

• # 🇭🇺 Attila Balázs (third round, retired)

• # 🇨🇳 Zhang Zhizhen (second round)

• # 🇸🇰 Martin Kližan (second round)

• # 🇮🇹 Federico Gaio (champion)

• # 🇦🇹 Sebastian Ofner (second round)

• # Robin Haase (final, retired)

• # 🇮🇹 Roberto Marcora (second round)

• # 🇺🇿 Denis Istomin (third round)

• # 🇨🇦 Peter Polansky (third round)

• # 🇰🇿 Dmitry Popko (semifinals)

• # 🇮🇳 Ramkumar Ramanathan (quarterfinals)

• # Botic van de Zandschulp (third round)