2021 Wolffkran Open – Singles

Marc-Andrea Hüsler was the defending champion but lost in the first round to Mats Rosenkranz.

Oscar Otte won the title after defeating Lukáš Lacko 6–4, 6–4 in the final.

Seeds
• # 🇦🇺 Jordan Thompson (first round)

• # 🇨🇿 Jiří Veselý (first round)

• # 🇮🇹 Andreas Seppi (second round)

• # 🇩🇪 Yannick Hanfmann (first round)

• # 🇩🇪 Oscar Otte (champion)

• # 🇨🇿 Tomáš Macháč (second round)

• # 🇺🇸 Maxime Cressy (semifinals)

• # 🇫🇷 Quentin Halys (semifinals)