2021 Amex-Istanbul Challenger – Singles

Ilya Ivashka was the defending champion but chose not to defend his title.

Arthur Rinderknech won the title after defeating Benjamin Bonzi 4–6, 7–6(7–1), 7–6(7–3) in the final.

Seeds
• # 🇨🇴 Daniel Elahi Galán (first round)

• # 🇧🇷 Thiago Seyboth Wild (first round)

• # 🇫🇷 Antoine Hoang (quarterfinals)

• # 🇦🇷 Facundo Bagnis (second round)

• # 🇮🇳 Prajnesh Gunneswaran (first round, retired)

• # 🇮🇹 Lorenzo Musetti (second round)

• # 🇸🇰 Jozef Kovalík (semifinals)

• # 🇯🇵 Go Soeda (quarterfinals, withdrew)