2016 Citi Open – Men's singles

Kei Nishikori was the defending champion, but chose not to participate this year. Second-seeded Gaël Monfils won the title, defeating Ivo Karlović in the final: 5–7, 7–6(8–6), 6–4.

Seeds
All seeds receive a bye into the second round. • 🇺🇸 John Isner (quarterfinals)

• 🇫🇷 Gaël Monfils (champion)

• 🇦🇺 Bernard Tomic (third round)

• 🇫🇷 Benoît Paire (quarterfinals)

• 🇺🇸 Steve Johnson (semifinals)

• 🇺🇸 Jack Sock (quarterfinals)

• 🇩🇪 Alexander Zverev (semifinals)

• 🇺🇸 Sam Querrey (quarterfinals)

• Kevin Anderson (second round)

• 🇷🇸 Viktor Troicki (second round)

• 🇺🇦 Alexandr Dolgopolov (third round)

• 🇧🇬 Grigor Dimitrov (second round)

• Ivo Karlović (final)

• 🇱🇺 Gilles Müller (third round)

• 🇨🇾 Marcos Baghdatis (third round)

• Borna Ćorić (third round)

Seeds
The top four seeds received a bye into the qualifying competition. • # 🇺🇸 Dennis Novikov (qualifying competition)

• # 🇫🇷 Vincent Millot (qualified)

• # 🇺🇸 Jared Donaldson (qualified)

• # 🇺🇸 Ryan Harrison (qualified)

• # 🇦🇺 Matthew Barton (qualifying competition)

• # 🇦🇺 James Duckworth (qualified)

• # 🇺🇸 Alexander Sarkissian (qualifying competition)

• # 🇮🇱 Amir Weintraub (qualifying competition)

• # 🇨🇴 Alejandro Falla (qualifying competition, retired)

• # 🇺🇸 Ernesto Escobedo (qualified)

• # 🇦🇺 Marinko Matosevic (qualifying competition)

• # 🇺🇸 Alex Kuznetsov (qualified)

Qualifiers
• # 🇺🇸 Ernesto Escobedo

• # 🇫🇷 Vincent Millot

• # 🇺🇸 Jared Donaldson

• # 🇺🇸 Ryan Harrison

• # 🇺🇸 Alex Kuznetsov

• # 🇦🇺 James Duckworth