2019 Oracle Challenger Series – Houston – Men's singles

Bradley Klahn was the defending champion but lost in the third round to Michael Mmoh.

Marcos Giron won the title after defeating Ivo Karlović 7–5, 6–7(5–7), 7–6(11–9) in the final.

Seeds
All seeds receive a bye into the second round. • # 🇺🇸 Tennys Sandgren (third round)

• # 🇺🇸 Bradley Klahn (third round)

• # Ivo Karlović (final)

• # 🇺🇸 Marcos Giron (champion)

• # Jason Jung (quarterfinals)

• # 🇦🇺 Christopher O'Connell (semifinals)

• # Darian King (second round)

• # 🇺🇸 Mitchell Krueger (semifinals)

• # 🇷🇺 Alexey Vatutin (third round)

• # 🇺🇸 Donald Young (second round)

• # 🇪🇸 Adrián Menéndez Maceiras (third round)

• # 🇷🇸 Peđa Krstin (third round)

• # 🇺🇸 Jenson Brooksby (third round)

• # 🇺🇸 Michael Mmoh (quarterfinals, retired)

• # 🇺🇸 Michael Redlicki (quarterfinals)

• # 🇺🇸 Sekou Bangoura (third round)