2018 German Open – Singles

Leonardo Mayer was the defending champion, but lost in the final to Nikoloz Basilashvili, 4–6, 6–0, 5–7. This was Basilashvili's first ATP World Tour title, as well as the first ATP title won by a Georgian player since Alexander Metreveli.

Seeds
• #🇦🇹 Dominic Thiem (quarterfinals)

• #🇦🇷 Diego Schwartzman (quarterfinals)

• #🇪🇸 Pablo Carreño Busta (quarterfinals)

• #🇧🇦 Damir Džumhur (first round)

• #🇩🇪 Philipp Kohlschreiber (first round)

• #🇮🇹 Marco Cecchinato (first round)

• #🇫🇷 Richard Gasquet (second round, withdrew)

• #🇪🇸 Fernando Verdasco (second round)

Seeds
• # Nikoloz Basilashvili (qualified)

• # 🇸🇰 Jozef Kovalík (qualified)

• # 🇫🇷 Corentin Moutet (qualified)

• # 🇮🇹 Lorenzo Sonego (first round)

• # 🇸🇰 Martin Kližan (first round)

• # 🇧🇷 Thiago Monteiro (qualifying competition, Lucky loser)

• # 🇫🇷 Calvin Hemery (first round)

• # 🇦🇷 Carlos Berlocq (first round)

Qualifiers
• # Nikoloz Basilashvili

• # 🇸🇰 Jozef Kovalík

• # 🇫🇷 Corentin Moutet

• # 🇩🇪 Daniel Masur

Lucky loser

 * 1) 🇧🇷 Thiago Monteiro