2019 OEC Kaohsiung – Singles

The 2019 OEC Kaohsiung-Singles was a men's tennis tournament held from September 16 to September 22, 2019, at Kaohsiung, Taiwan. Gaël Monfils was the defending champion but chose not to defend his title.

John Millman won the title after defeating Marc Polmans 6–4, 6–2 in the final.

Seeds
All seeds receive a bye into the second round. • # 🇵🇱 Kamil Majchrzak (third round)

• # 🇮🇳 Prajnesh Gunneswaran (third round)

• # 🇦🇺 John Millman (champion)

• # 🇦🇺 Bernard Tomic (withdrew)

• # 🇨🇿 Jiří Veselý (quarterfinals)

• # Jason Jung (third round)

• # 🇯🇵 Go Soeda (third round)

• # 🇯🇵 Yūichi Sugita (third round)

• # 🇦🇺 Alex Bolt (quarterfinals)

• # 🇦🇺 Marc Polmans (final)

• # 🇯🇵 Yasutaka Uchiyama (third round)

• # 🇨🇦 Steven Diez (semifinals)

• # 🇦🇺 Andrew Harris (third round)

• # 🇪🇸 Enrique López Pérez (quarterfinals)

• # 🇯🇵 Yosuke Watanuki (second round)

• # 🇯🇵 Hiroki Moriya (third round)