The forward, 40, has been without a club since being released by Sampdoria in July.
And he has now confirmed he is hanging up his boots, citing his “unacceptable physical condition” as the reason for his decision.
Speaking to Sky Sports Italia, he said: “I am retiring, I am obliged to do so.
“I am a free agent, but I am in an unacceptable physical condition to be able to go out on the field.
“I will have a lot of time to think about what my path to follow will now be.”
Quagliarella earned 28 caps for his country, scoring eight goals.
He made 25 appearances between 2007 and 2010 – scoring a sumptuous chip at the World Cup in South Africa in Italy‘s final group match, before they were eliminated.
After nearly a decade away from the national team, he then returned to the Italy set-up in 2019 following a sensational season for Sampdoria in which he scored 26 goals in 39 games.
He scored two goals in three matches upon his return to international football, but was not picked again.
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Quagliarella spent his entire career playing in Italy, featuring for a host of the country’s biggest sides.
Following spells at Torino, Fiorentina, Chieti, Ascoli, Sampdoria and Udinese, he enjoyed one year at Napoli before he signed for Juventus.
He scored 30 goals in 102 games for The Old Lady, winning three Serie A titles.
He then returned to Torino in 2014, before ending his career with seven years at Sampdoria in which he bagged 92 goals in 251 games.
Reacting to his retirement, Juventus tweeted: “Have you noticed how much applause the Juventus public reserved for Fabio Quagliarella every time he returned to Turin as a rival of the ‘bianconeri’?
“Unfortunately we are speaking in the past tense because Fabio has just announced his retirement.
“True champion, true man, supreme talent. Fabio is one of those players who stay in the heart.
“For his goals, which have always ranged between the beautiful and the impossible, for the effort he put into every shirt he wore.”
Sampdoria also responded to the news, saying: “Fabio Quagliarella, a footballing icon. Good luck in what’s to come, legend.”