2021 Bratislava Open – Singles

Norbert Gombos was the defending champion but lost in the second round to Filip Horanský.

Tallon Griekspoor won the title after defeating Sebastián Báez 7–6(8–6), 6–3 in the final.

Seeds
• # 🇸🇰 Norbert Gombos (second round)

• # 🇦🇷 Federico Coria (second round)

• # 🇧🇴 Hugo Dellien (first round)

• # 🇸🇰 Jozef Kovalík (second round)

• # Tallon Griekspoor (champion)

• # 🇦🇷 Juan Manuel Cerúndolo (second round)

• # Blaž Rola (first round)

• # Frederico Ferreira Silva (second round)