Javier Adelmar Zanetti was born in Buenos Aires with Italian origins to working-class parents and grew up in the harbour area in the Dock Sud district, one of the city's most notorious areas. His father Rodolfo was a bricklayer and his mother Violeta Bonnazola was a cleaner. He began playing football on a field in the city suburbs, maintaining the pitch in his spare time. When he was a teenager, he tried out for local club Independiente's youth academy but was ultimately rejected and told that he lacked the physique to succeed in the game.

On 20 October 2010, at 37 years and 71 days, Zanetti became the oldest player to score in the Champions League when he netted in the opening minute of Inter's 4-3 group stage win over Tottenham Hotspur at the San Siro. This was only his second ever Champions League goal; his first came in December 1998 in a match in a 2-0 win against Sturm Graz. He scored one of Inter's goals in their 3-0 win against Seongnam Ilhwa Chunma at the 2010 FIFA Club World Cup, which they eventually won, although Inter missed out on the UEFA Super Cup that season.  On 19 January 2011, Zanetti overtook Inter legend Giuseppe Bergomi in Serie A appearances, his 520th match in Serie A, all for Inter. On 11 May 2011, Zanetti made his 1,000th appearance as a professional footballer playing for Inter against Roma in the second leg of the Coppa Italia semi-final. On 20 September 2011, Zanetti made the all-time appearance record in a Serie A clash against Novara, surpassing Giuseppe Bergomi.  On 10 March 2013, Zanetti played in his 600th Serie A match for Inter, a 1-0 loss to Bologna at the San Siro. On 21 April 2014, in the 1-0 home win against Parma, Zanetti played his 1,100th official match and became the player with the fourth-most appearances of all time.  On 29 April 2014, Inter chairman Erick Thohir announced that Zanetti would retire at the end of the 2013-14 season and become a club director. Zanetti's last competitive match at the San Siro was a 4-1 victory over Lazio on 10 May 2014. He came on as a substitute for Jonathan in the 52nd minute and wore a special armband featuring the names of every player he had played with during his career at Inter. He retired after the last game of the season, which he started as centre-back in a 2-1 away defeat to Chievo on 18 May.

Did he win any other matches
He retired after the last game of the season, which he started as centre-back in a 2-1 away defeat to Chievo on 18 May.