Ignacio Nacho Piatti (born 4 February 1985) is an Argentine professional footballer who currently plays as a midfielder for the Montreal Impact in Major League Soccer. He has played for top division clubs in South America, Europe and North America.
Piatti has played professional football in Europe with Saint-Étienne and Lecce. In his native Argentina, he has played for Chacarita Juniors, Gimnasia LP, and Independiente.
On 2 July 2014, Piatti signed a transfer agreement with the Montreal Impact of Major League Soccer.