2023 Heilbronner Neckarcup – Singles

Daniel Altmaier was the defending champion but chose not to defend his title.

Matteo Arnaldi won the title after defeating Facundo Díaz Acosta 7–6(7–4), 6–1 in the final.

Seeds
• # 🇮🇹 Marco Cecchinato (first round)

• # 🇪🇸 Jaume Munar (quarterfinals)

• # 🇨🇴 Daniel Elahi Galán (quarterfinals)

• # 🇦🇹 Dominic Thiem (second round)

• # 🇮🇹 Matteo Arnaldi (champion)

• # 🇭🇺 Fábián Marozsán (second round)

• # 🇩🇪 Oscar Otte (first round)

• # Pavel Kotov (quarterfinals)