2014 Citi Open – Men's singles

Juan Martín del Potro was the defending champion, but was unable to participate this year due to a wrist injury.

Milos Raonic won the title, defeating Vasek Pospisil, 6–1, 6–4, in the first-ever all-Canadian final on the ATP World Tour.

Seeds
All seeds received a bye into the second round.

🇨🇿 Tomáš Berdych (third round) 🇨🇦 Milos Raonic (champion) 🇧🇬 Grigor Dimitrov (withdrew due to flu-like symptoms) 🇯🇵 Kei Nishikori (quarterfinals) 🇺🇸 John Isner (second round) 🇫🇷 Richard Gasquet (semifinals) Kevin Anderson (quarterfinals) 🇪🇸 Feliciano López (second round) Ivo Karlović (third round) 🇨🇴 Santiago Giraldo (quarterfinals) 🇨🇿 Radek Štěpánek (second round) 🇫🇷 Jérémy Chardy (second round) 🇨🇦 Vasek Pospisil (final) 🇦🇺 Lleyton Hewitt (third round) 🇺🇿 Denis Istomin (third round) Lu Yen-hsun (second round) 🇫🇷 Julien Benneteau (second round)

Seeds
• 🇦🇺 Sam Groth (qualifying competition, Lucky loser)

• 🇯🇵 Yūichi Sugita (qualified)

• 🇮🇳 Yuki Bhambri (first round, retired)

• 🇺🇸 Rajeev Ram (qualified)

• 🇷🇴 Marius Copil (qualifying competition)

• 🇺🇸 Alex Kuznetsov (qualified)

• 🇺🇦 Illya Marchenko (qualified)

• 🇨🇳 Zhang Ze (withdrew)

• 🇫🇷 Michaël Llodra (first round, retired)

• Gonzalo Lama (first round)

• 🇪🇨 Emilio Gómez (qualifying competition)

• 🇨🇦 Steven Diez (first round)

Qualifiers
• # 🇺🇸 Robby Ginepri

• # 🇯🇵 Yūichi Sugita

• # 🇺🇸 Jared Donaldson

• # 🇺🇸 Rajeev Ram

• # 🇺🇦 Illya Marchenko

• # 🇺🇸 Alex Kuznetsov

Lucky losers

 * 1) 🇦🇺 Sam Groth