See main article: 2014 Citi Open.
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.[1]
All seeds received a bye into the second round.
See also: 1 and 1. 
Tomáš Berdych (third round)
See also: 2 and 4. 
Milos Raonic (champion)
See also: 3. Grigor Dimitrov (withdrew due to flu-like symptoms)
See also: 4 and 2. 
Kei Nishikori (quarterfinals)
See also: 5 and 4. 
John Isner (second round)
See also: 6 and 2. 
Richard Gasquet (semifinals)
See also: 7 and 3. Kevin Anderson (quarterfinals)
See also: 8 and 1. 
Feliciano López (second round)
See also: 9 and 4. Ivo Karlović (third round)
See also: 10 and 1. 
Santiago Giraldo (quarterfinals)
See also: 11 and 3. Radek Štěpánek (second round)
See also: 12 and 2. Jérémy Chardy (second round)
See also: 13 and 1. Vasek Pospisil (final)
See also: 14 and 4. 
Lleyton Hewitt (third round)
See also: 15 and 3. 
Denis Istomin (third round)
See also: 16 and 2. Lu Yen-hsun (second round)
See also: 17 and 3. Julien Benneteau (second round)