- Date of birth: November 25, 1977
- Birthplace: Buenos Aires, Argentina
- Residence: Buenos Aires, Argentina
- Height: 6'1'' (1.75 m)
- Weight: 190 lbs (86 kg)
- Plays: Right-handed
Guillermo Canas's highest singles ranking was 8th (June 2005). He started playing at age 7 and turned professional in 1995.
He plays a defensive counter-punching game from the baseline, and utilises his retrieving skills in order to frustrate opponents. He uses a double-handed backhand and his favourite surface is clay, but he is adept on hardcourt and grass too.
After a year of suspension for doping, Canas returned to the circuit on September 2006 at the challenger of Belem, Brazil. He holds a record of 5 victories and 2 defeats (3:1 in singles) in Davis Cup matches.
- Career record: 250–190
- Career titles:
- Highest ranking: No. 8 (June 6, 2005)
Grand Slam results
- Australian Open: 4r (2004, 2005)
- French Open: QF (2002, 2005, 2007)
- Wimbledon: 4R (2001)
- US Open: 3R (2004)
- Career record: 61–82
- Career titles: 2
- Highest ranking: No. 47 (July 15, 2002)