2021 French Open – Boys' singles

Luca Van Assche won the title, defeating Arthur Fils in an all-French final, 6–4, 6–2. This was the first Grand Slam junior tournament with all-French semifinalists.

Dominic Stricker was the defending champion, but was no longer eligible to participate in junior events.

Seeds
• 🇨🇳 Shang Juncheng (quarterfinals)

• 🇺🇸 Bruno Kuzuhara (third round)

• 🇧🇷 Pedro Boscardin Dias (third round)

• 🇬🇧 Jack Pinnington Jones (first round)

• 🇫🇷 Giovanni Mpetshi Perricard (semifinals)

• Jérôme Kym (second round)

• 🇺🇸 Dali Blanch (second round)

• 🇪🇸 Daniel Rincón (quarterfinals)

• 🇫🇷 Sean Cuenin (semifinals)

• 🇺🇸 Alexander Bernard (first round)

• 🇧🇪 Pierre Yves Bailly (second round)

• 🇪🇪 Mark Lajal (first round)

• 🇫🇷 Luca Van Assche (champion)

• 🇫🇷 Arthur Fils (final)

• 🇺🇸 Samir Banerjee (first round)

• 🇺🇦 Viacheslav Bielinskyi (quarterfinals)