2021 Heilbronner Neckarcup – Singles

Filip Krajinović was the defending champion but chose not to defend his title.

Bernabé Zapata Miralles won the title after defeating Daniel Elahi Galán 6–3, 6–4 in the final.

Seeds
• # 🇨🇿 Jiří Veselý (first round)

• # 🇩🇪 Yannick Hanfmann (second round)

• # 🇦🇹 Dennis Novak (semifinals)

• # 🇨🇴 Daniel Elahi Galán (final)

• # 🇯🇵 Taro Daniel (quarterfinals)

• # 🇺🇸 Denis Kudla (first round)

• # 🇩🇪 Philipp Kohlschreiber (quarterfinals)

• # 🇺🇸 Mackenzie McDonald (semifinals)