2008 US Open – Boys' singles

Ričardas Berankis was the defending champion but, no longer competing in junior tennis, did not defend his title.

Grigor Dimitrov won in the final 6–4, 6–3, against Devin Britton.

Seeds
• # Yang Tsung-hua (semifinals)

• # 🇦🇺 Bernard Tomic (first round)

• # 🇧🇬 Grigor Dimitrov (champion)

• # 🇫🇮 Henri Kontinen (quarterfinals)

• # 🇲🇽 César Ramírez (second round)

• # 🇫🇷 Guillaume Rufin (third round)

• # 🇧🇷 José Pereira (first round)

• # 🇧🇷 Henrique Cunha (first round)

• # 🇺🇸 Ryan Harrison (third round)

• # 🇦🇷 Juan Vazquez-Valenzuela (second round)

• # 🇩🇪 Cedrik-Marcel Stebe (quarterfinals)

• # 🇮🇳 Yuki Bhambri (second round)

• # 🇺🇸 Bradley Klahn (third round)

• # Marcelo Arévalo (third round)

• # 🇹🇭 Peerakit Siributwong (third round)

• # (withdrew)