2018 U.S. Men's Clay Court Championships – Singles

Steve Johnson was the defending champion and successfully defended his title, defeating Tennys Sandgren in the final, 7–6(7–2), 2–6, 6–4.

Seeds
The top four seeds received a bye into the second round. • #🇺🇸 John Isner (quarterfinals)

• #🇺🇸 Sam Querrey (second round)

• #🇺🇸 Jack Sock (quarterfinals)

• #🇦🇺 Nick Kyrgios (quarterfinals)

• #🇪🇸 Fernando Verdasco (first round)

• #🇺🇸 Steve Johnson (champion)

• #🇺🇸 Ryan Harrison (second round)

• #🇺🇸 Tennys Sandgren (final)

Seeds
• # 🇬🇧 Cameron Norrie (first round)

• # 🇺🇸 Denis Kudla (qualified)

• # 🇧🇷 Thomaz Bellucci (first round)

• # 🇺🇸 Michael Mmoh (first round)

• # 🇺🇸 Bradley Klahn (qualifying competition)

• # 🇺🇸 Dennis Novikov (qualifying competition)

• # 🇦🇺 Akira Santillan (qualifying competition)

• # Darian King (first round)

Qualifiers
• # 🇯🇵 Yoshihito Nishioka

• # 🇺🇸 Denis Kudla

• # 🇺🇸 Stefan Kozlov

• # 🇷🇸 Miomir Kecmanović