2021 Tennis Napoli Cup – Singles

Jozef Kovalík was the defending champion but chose not to defend his title.

Tallon Griekspoor won the title after defeating Andrea Pellegrino 6–3, 6–2 in the final.

Seeds
• # 🇮🇹 Stefano Travaglia (semifinals)

• # 🇸🇰 Andrej Martin (second round)

• # 🇩🇪 Yannick Hanfmann (second round)

• # Tallon Griekspoor (champion)

• # 🇨🇿 Zdeněk Kolář (second round)

• # 🇮🇹 Alessandro Giannessi (first round, retired)

• # 🇮🇹 Gian Marco Moroni (quarterfinals)

• # 🇮🇹 Lorenzo Giustino (first round)