2018 Knoxville Challenger – Singles

Filip Peliwo was the defending champion but chose not to defend his title.

Reilly Opelka won the title after defeating Bjorn Fratangelo 7–5, 4–6, 7–6(7–2) in the final.

Seeds
• # 🇺🇸 Tennys Sandgren (second round)

• # 🇪🇸 Marcel Granollers (first round)

• # 🇺🇸 Bradley Klahn (second round)

• # 🇺🇸 Michael Mmoh (quarterfinals, withdrew)

• # 🇺🇸 Tim Smyczek (quarterfinals)

• # Jason Jung (second round)

• # 🇨🇦 Peter Polansky (second round)

• # 🇺🇸 Reilly Opelka (champion)