The 38-year-old former Juventus, Inter Milan and AC Milan midfielder made a late appearance for his club New York City against Columbus Crew, the day before announcing the end of his playing career.
"Not only my adventure in NY comes to an end, but my journey as a football player as well," Pirlo wrote on his Twitter account.
"That is why I would like to take the opportunity to thank my family and my children for the support and love they always give me, every team that I had the honour to play for, every team-mate I have been pleased to play alongside, all the people that made my career so incredible, and last but not least, all the fans around the world that always showed me support.
Pirlo headed for the United States at the end of the 2014-2015 season after winning another Serie A title with Juventus -- his sixth in total -- including two with AC Milan.
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He had already announced that this season would be his last as a player but his team lost his final game Sunday's Major League Soccer playoff match against Colombus Crew.
Pirlo, who started his career in Brescia, also played at Inter Milan and Reggina before joining AC Milan, where he won two Serie A crowns and two Champions League trophies in 2003 and 2007.
In 2011, while out of contract he joined Juventus, a deal which Italian international goalkeeper Gianluigi Buffon dubbed the "the deal of the century".
In Turin, Pirlo continued to impress despite his age winning four titles and an Italian Cup.
His final match in Europe was in Juventus's Champions League final defeat in 2015 to Barcelona.
Capped 116 times for Italy, scoring 13 goals, during a 13-year career until 2015, Pirlo played his final two years with New York City FC.