2018 Koblenz Open – Singles

Ruben Bemelmans was the defending champion but withdrew as he qualified for the 2018 Australian Open.

Mats Moraing won the title after defeating Kenny de Schepper 6–2, 6–1 in the final.

Seeds
• # 🇷🇺 Andrey Kuznetsov (first round)

• # 🇮🇹 Marco Cecchinato (second round)

• # 🇺🇦 Sergiy Stakhovsky (semifinals)

• # 🇩🇪 Oscar Otte (first round)

• # 🇩🇪 Yannick Maden (quarterfinals)

• # 🇫🇷 Kenny de Schepper (final)

• # 🇸🇰 Andrej Martin (first round)

• # 🇪🇸 Tommy Robredo (first round)