The 32-year-old moved to China in the summer from Genoa, but Fiorentina’s deal includes an option to buy the 2006 World Cup winner at the end of the season.
A statement on the club’s website said: “ACF Fiorentina announces the acquisition on a temporary basis, with the option to buy, the rights to the player Alberto Gilardino from Guangzhou Evergrande Football Club until June 2015.”
Gilardino arrived in Italy over the weekend to complete the formalities of his return to the Viola, where he played from 2008 to 2012, scoring 59 goals in 143 appearances in all competitions after his move from AC Milan.
On arrival at Fiorentina, Gilardino said: “I will return here with great desire. I say thank you to the president and the club staff who wanted me here.”
After leaving Fiorentina, Gilardino signed for Genoa, with a spell at Bologna on loan, before moving to China.
Gilardino, who has scored 19 goals in 57 appearances for Italy, will be formally introduced at a press conference on Wednesday.