2021 Eastbourne International – Men's singles

Alex de Minaur defeated Lorenzo Sonego in the final, 4–6, 6–4, 7–6(7–5), to win the men's singles tennis title at the 2021 Eastbourne International. It was De Minaur's fifth career ATP Tour singles title and his first on grass. Sonego was contesting in his second grass final to win his third career title.

Taylor Fritz was the defending champion from when the event was last held in 2019, but he withdrew before the beginning of the tournament after incurring a knee injury during the French Open.

Seeds
The top four seeds received a bye into the second round. • # 🇫🇷 Gaël Monfils (second round)

• # 🇦🇺 Alex de Minaur (champion)

• # 🇮🇹 Lorenzo Sonego (final)

• # Nikoloz Basilashvili (withdrew)

• # 🇺🇸 Reilly Opelka (withdrew)

• # 🇪🇸 Alejandro Davidovich Fokina (second round, retired)

• # 🇪🇸 Albert Ramos Viñolas (first round)

• # 🇰🇿 Alexander Bublik (quarterfinals)

• # 🇬🇧 Cameron Norrie (withdrew)

Seeds
• # 🇰🇷 Kwon Soon-woo (first round, lucky loser)

• # 🇸🇰 Norbert Gombos (qualifying competition, lucky loser)

• # 🇧🇾 Ilya Ivashka (qualified)

• # 🇮🇹 Andreas Seppi (qualifying competition, lucky loser)

• # 🇦🇺 James Duckworth (qualified)

• # 🇸🇪 Mikael Ymer (qualified)

• # Kevin Anderson (first round)

• # 🇰🇿 Mikhail Kukushkin (qualified)

Qualifiers
• # 🇦🇺 James Duckworth

• # 🇸🇪 Mikael Ymer

• # 🇧🇾 Ilya Ivashka

• # 🇰🇿 Mikhail Kukushkin

Lucky losers
• # 🇬🇧 Alastair Gray

• # 🇦🇺 Max Purcell

• # 🇮🇹 Andreas Seppi

• # 🇸🇰 Norbert Gombos

• # 🇰🇷 Kwon Soon-woo