James Gandolfini -- who famously played Tony Soprano on "The Sopranos" -- died earlier today in Italy ... TMZ has learned.
Gandolfini is believed to have suffered a heart attack. He was 51.
Gandolfini was in Italy to attend the 59th Taormina Film Festival in Sicily -- and he was scheduled to participate in a festival event this weekend with Italian director Gabriele Muccino.
