2021 Nur-Sultan Challenger – Singles

There was no defending champion as the last edition of the tournament was canceled due to the COVID-19 pandemic.

Mackenzie McDonald won the title after defeating Jurij Rodionov 6–1, 6–2 in the final.

Seeds
• # 🇰🇿 Mikhail Kukushkin (first round)

• # 🇷🇺 Evgeny Donskoy (first round)

• # 🇩🇪 Cedrik-Marcel Stebe (withdrew)

• # 🇮🇳 Prajnesh Gunneswaran (semifinals)

• # Henri Laaksonen (semifinals)

• # 🇦🇹 Jurij Rodionov (final)

• # 🇸🇰 Martin Kližan (quarterfinals)

• # Blaž Rola (first round)