Guillermo Ignacio Cañas, often referred to as Willy Cañas, is a retired tennis player from Argentina. He was born in Buenos Aires and named after Argentine tennis star Guillermo Vilas. Cañas won the Canada Masters in 2002, and reached the quarterfinal stage of the French Open in 2002, 2005 and 2007. His career-high singles ranking was world No. 8, achieved in June 2005. After being suspended in August 2005, Cañas returned to the circuit in September 2006 at ATP Challenger level.