The Spanish media reported Florentino Perez is close to signing Kaka on a pre-contract agreement as part of his bid to return as Real president.
Galliani said: "Perez has not been elected president of Real and cannot therefore make any moves.
"In any case I'm certain that if one day Florentino wanted to sign Kaka he would come directly to me. Hence, I am calm.
"Kaka is not for sale and Florentino will eventually realise this."
The 26-year-old Kaka, who is under contract with the Rossoneri club through June 2013, turned down a record-breaking move to Manchester City in January.