The Rossoneri director has hailed the Brazilian midfielder following his fine performances since his return to Serie A
The attacking midfielder, 31, returned to the San Siro side at the start of the 2013-14 campaign after a four-year spell at Real Madrid.
And Galliani has stressed that Kaka is held in very high regard by the Rossoneri faithful.
"Kaka is a true Milan legend. Everybody at the club loves him," Galliani told RMC.
"He has entered the hearts of all the Milan fans in his own special way.
"At Milan, we have had legends like Maldi and Baresi. It is probably fair to say that the fans' affection for Kaka is equally big.
"There were people who feared that he was no longer the Kaka from before, but he has been doing very well and we are all delighted with him."
Kaka has made 12 Serie A appearances for Milan since his return, scoring five goals in the process.
He recently surpassed the 100-goal mark for the San Siro side in the 3-0 win over Atalanta.