2019 Koblenz Open – Singles

Mats Moraing was the defending champion but chose not to defend his title.

Gianluca Mager won the title after defeating Roberto Ortega Olmedo 2–6, 7–6(8–6), 6–2 in the final.

Seeds
All seeds receive a bye into the second round. • # 🇳🇴 Casper Ruud (third round)

• # 🇩🇪 Yannick Maden (third round)

• # 🇷🇺 Alexey Vatutin (quarterfinals, retired)

• # 🇮🇹 Andrea Arnaboldi (second round)

• # 🇩🇪 Daniel Brands (second round)

• # 🇬🇧 James Ward (second round)

• # 🇸🇪 Mikael Ymer (quarterfinals)

• # 🇧🇪 Arthur De Greef (second round)

• # 🇨🇿 Adam Pavlásek (third round)

• # 🇩🇪 Tobias Kamke (second round)

• # 🇸🇰 Filip Horanský (third round)

• # 🇫🇷 Kenny de Schepper (third round)

• # 🇨🇿 Zdeněk Kolář (second round)

• # Tallon Griekspoor (semifinals)

• # Thiemo de Bakker (third round)

• # 🇧🇾 Uladzimir Ignatik (third round)