2021 Delray Beach Open – Singles

Reilly Opelka was the defending champion, but withdrew from the event.

Hubert Hurkacz won the title, defeating Sebastian Korda in the final, 6–3, 6–3. Hurkacz did not face an opponent ranked inside the top 100 during his title run.

Seeds
The top four seeds receive a bye into the second round.

• # Cristian Garín (second round)

• #🇺🇸 John Isner (quarterfinals)

• #🇫🇷 Adrian Mannarino (second round)

• #🇵🇱 Hubert Hurkacz (champion)

• #🇺🇸 Tommy Paul (second round)

• #🇺🇸 Sam Querrey (second round)

• #🇪🇸 Pablo Andújar (first round)

• #🇺🇸 Frances Tiafoe (quarterfinals)

Seeds
• # Marcelo Tomás Barrios Vera (first round)

• # Viktor Galović (qualifying competition)

• # Gonçalo Oliveira (qualifying competition)

• # 🇧🇷 Pedro Sakamoto (first round)

• # 🇪🇨 Roberto Quiroz (qualified)

• # 🇺🇸 Alexander Ritschard (first round, retired)

• # 🇺🇸 Kevin King (qualified)

• # 🇩🇪 Johannes Härteis (first round, retired)

Qualifiers
• # 🇺🇸 Christian Harrison

• # 🇪🇨 Roberto Quiroz

• # 🇺🇸 Kevin King

• # 🇺🇸 Donald Young