2023 Hamburg Ladies & Gents Cup – Men's singles

Alexander Ritschard was the defending champion but chose not to defend his title.

Illya Marchenko won the title after defeating Dennis Novak 6–2, 6–3 in the final.

Seeds
• # 🇦🇹 Dennis Novak (final)

• # 🇦🇺 Adam Walton (quarterfinals)

• # 🇭🇺 Máté Valkusz (quarterfinals)

• # 🇩🇪 Rudolf Molleker (first round)

• # Frederico Ferreira Silva (first round)

• # 🇹🇷 Cem İlkel (second round)

• # 🇦🇹 Maximilian Neuchrist (second round)

• # 🇺🇦 Oleksii Krutykh (first round)