2021 President's Cup – Men's singles

Evgeny Donskoy was the defending champion but chose not to defend his title.

Max Purcell won the title after defeating Jay Clarke 3–6, 6–4, 7–6(8–6) in the final.

Seeds
• # 🇷🇺 Roman Safiullin (quarterfinals)

• # 🇺🇿 Denis Istomin (first round)

• # 🇬🇧 Jay Clarke (final)

• # 🇦🇺 Max Purcell (champion)

• # Borna Gojo (semifinals)

• # 🇺🇦 Sergiy Stakhovsky (second round)

• # 🇨🇦 Peter Polansky (semifinals)

• # 🇫🇷 Hugo Grenier (first round)