|Full name||Gonzalo Nicolás Martínez|
|Date of birth||13 June 1993|
|Place of birth||Guaymallén, Mendoza, Argentina|
|Height||1.70 m (5 ft 7 in)|
* Senior club appearances and goals counted for the domestic league only and correct as of 7 March 2020|
‡ National team caps and goals correct as of 11 September 2018
Martínez joined River Plate in January 2015. Martínez made his club debut on 16 February 2015 against Club Atlético Sarmiento in a 1–4 away win. On 25 April 2015, his former team Huracán beat River Plate for the Supercopa Argentina title.
In the Copa Libertadores, Martínez was fouled in the quarter-final first leg match against Boca Juniors, a match River Plate would go on to win. Martínez won two more Copa Argentina in a row, in 2016 and 2017. Martínez added two Recopa Sudamericanas, in 2015 and 2016. Martínez also won two Copa Libertadores, in 2015 and 2018, as well as one 2015 Suruga Bank Championship, in which he scored in River's 3–0 win over Gamba Osaka. He was instrumental in obtaining his first Supercopa Argentina title against Boca.
On 9 December 2018, Martínez scored his side's third goal to seal a 3–1 win, 5–3 aggregate victory, over Boca Juniors in the second leg of the Copa Libertadores held at Real Madrid's Bernabéu Stadium. Following the victory, he announced that he would be joining MLS side Atlanta United after the FIFA Club World Cup, as the American club met his $17 million release clause.
On 8 September 2018, Martínez made his Argentina debut in a 3–0 victory over Guatemala. He started the match, scored from the penalty spot after a handball by Elías Vásquez midway through the first half, and was replaced by Franco Vázquez in the 56th minute.
|1.||7 September 2018||Los Angeles Memorial Coliseum, Los Angeles, United States||Guatemala||1–0||3–0||Friendly|
|Huracán||2011–12||Primera B Nacional||15||0||0||0||—||—||15||0|
|2012–13||Primera B Nacional||28||0||2||0||—||—||30||0|
|2013–14||Primera B Nacional||29||4||0||0||—||—||29||4|
|2014||Primera B Nacional||21||4||1||0||—||—||22||4|
|River Plate||2015||Primera División||24||4||2||0||17[a]||0||5[b]||1||49||5|
His nickname, Pity, refers to the wren ("pititorra"), from his native homeland of Mendoza, Argentina. He was given the nickname at the age of five, and does not respond to his given name, Gonzalo.