The 25-year-old joined the Serie A outfit from Atletico Paranaense in January 2011 and became regular first choice in goal last term.
Neto's deal at Stadio Artemio Franchi is now into its final six months, and Fiorentina announced on Saturday that the Brazilian will be moving on in the close-season.
"ACF Fiorentina must announce that goalkeeper Norberto Murara Neto today officially informed the club of his intention not to prolong his contract with the Viola. The decision is definitive," a club statement read.
"Neto was keen to make it known that his decision is entirely unrelated to financial motivations, with his desire to be free to decide his own future the sole reason behind his move."
Fiorentina return to Serie A action at bottom-placed Parma on Tuesday.
