2021 Atlanta Open – Singles

Alex de Minaur was the reigning champion from when the tournament was last held in 2019, but chose not to participate this year.

John Isner won his sixth Atlanta Open title, defeating Brandon Nakashima in the final, 7–6(10–8), 7–5.

Seeds
The top four seeds receive a bye into the second round. • # 🇨🇦 Milos Raonic (second round)

• # 🇮🇹 Jannik Sinner (second round)

• # 🇬🇧 Cameron Norrie (quarterfinals)

• # 🇺🇸 Reilly Opelka (quarterfinals)

• # 🇺🇸 Taylor Fritz (semifinals)

• # 🇺🇸 John Isner (champion)

• # 🇫🇷 Benoît Paire (second round, retired)

• # Lloyd Harris (first round)

Seeds
• # 🇩🇪 Peter Gojowczyk (qualified)

• # 🇦🇺 Christopher O'Connell (qualified)

• # 🇷🇺 Evgeny Donskoy (qualified)

• # Jason Jung (qualifying competition)

• # 🇺🇦 Illya Marchenko (first round)

• # 🇦🇹 Sebastian Ofner (qualifying competition, retired)

• # 🇸🇪 Elias Ymer (first round)

• # 🇯🇵 Go Soeda (first round)

Qualifiers
• # 🇩🇪 Peter Gojowczyk

• # 🇦🇺 Christopher O'Connell

• # 🇷🇺 Evgeny Donskoy

• # 🇺🇸 Bjorn Fratangelo