2021 Rafa Nadal Open – Singles

Emil Ruusuvuori was the defending champion but chose not to defend his title.

Lukáš Lacko won the title after defeating Yasutaka Uchiyama 5–7, 7–6(10–8), 6–1 in the final.

Seeds
• # 🇯🇵 Yasutaka Uchiyama (final)

• # 🇪🇸 Fernando Verdasco (quarterfinals)

• # 🇬🇧 Liam Broady (first round)

• # João Sousa (quarterfinals)

• # 🇦🇹 Sebastian Ofner (second round, retired)

• # Marcelo Tomás Barrios Vera (second round)

• # 🇵🇱 Kacper Żuk (first round)

• # Blaž Rola (first round)