2018 Australian Open – Boys' singles

Sebastian Korda, the son of 1998 men's singles champion Petr Korda, won the boys' singles tennis title at the 2018 Australian Open, defeating Tseng Chun-hsin in the final, 7–6(8–6), 6–4.

Zsombor Piros was the defending champion, but was no longer eligible to participate in junior events. He received a wildcard into the men's singles qualifying competition, where he lost to Bjorn Fratangelo in the second round.

Seeds
• # 🇷🇺 Timofey Skatov (quarterfinals)

• # 🇷🇸 Marko Miladinović (semifinals)

• # 🇦🇷 Sebastián Báez (second round)

• # 🇰🇷 Park Ui-sung (first round)

• # 🇫🇷 Hugo Gaston (quarterfinals)

• # Tseng Chun-hsin (final)

• # 🇺🇸 Sebastian Korda (champion)

• # 🇨🇴 Nicolás Mejía (first round)

• # 🇧🇷 Thiago Seyboth Wild (second round)

• # 🇦🇷 Juan Manuel Cerúndolo (first round)

• # 🇦🇷 Thiago Agustín Tirante (first round)

• # 🇷🇺 Alexey Zakharov (third round, retired)

• # 🇺🇸 Andrew Fenty (first round)

• # 🇨🇿 Ondřej Štyler (third round)

• # 🇯🇵 Naoki Tajima (first round)

• # 🇨🇿 Tomáš Macháč (first round)

Seeds
• # Damien Wenger (qualified)

• # Jesper de Jong (qualified)

• # 🇺🇸 Brian Shi (first round)

• # 🇰🇷 Han Seon-yong (qualifying competition)

• # Philip Henning (qualified)

• # 🇺🇦 Oleksii Krutykh (qualifying competition)

• # Duje Ajduković (qualified)

• # Aaron Schmid (first round)

• # 🇯🇵 Seita Watanabe (first round)

• # 🇫🇷 Jaimee Floyd Angele (qualified)

• # 🇮🇹 Giulio Zeppieri (qualified)

• # 🇪🇸 Alberto Colás Sánchez (qualifying competition)

• # Lodewijk Weststrate (qualifying competition; lucky loser)

• # 🇺🇿 Sergey Fomin (qualified)

• # 🇺🇸 Jaycer Lyeons (qualified)

• # 🇬🇧 Emile Hudd (qualifying competition)

Qualifiers
• # Damien Wenger

• # Jesper de Jong

• # 🇫🇷 Jaimee Floyd Angele

• # 🇺🇿 Sergey Fomin

• # Philip Henning

• # 🇮🇹 Giulio Zeppieri

• # Duje Ajduković

• # 🇺🇸 Jaycer Lyeons

Lucky losers
• # Lodewijk Weststrate