The actor, best known for playing mob boss Tony Soprano in the hit drama, was just 51 years old when he passed away after reportedly suffering a heart attack in Rome.
The stars of The Sopranos and bosses behind the Tv series were plunged into mourning upon hearing of his death, and have now offered their condolences.
David Chase, the show's creator, was one of the first to release a statement, which reads, "He was a genius. Anyone who saw him even in the smallest of his performances knows that. He is one of the greatest actors of this or any time. A great deal of that genius resided in those sad eyes. I remember telling him many times, 'You don't get it. You're like Mozart.' There would be silence at the other end of the phone. He wasn't easy sometimes. But he was my partner, he was my brother in ways I can't explain and never will be able to explain."
Lorraine Bracco, who played Tony Soprano's psychiatrist Dr. Jennifer Melfi, simply says, "We lost a giant today. I am utterly heartbroken."
Rocker/actor Steven Van Zandt, who played Tony's partner and strip-club owner Silvio Dante, wrote in a post on Facebook.com, "I have lost a brother and a best friend. The world has lost one of the greatest actors of all time. (My wife) Maureen and I send our deepest sympathy and love to (Gandolfini's wife) Deborah, (his kids) Michael, Lily, and all of Jimmy's family."
Co-star Joseph R. Gannascoli, who played Vito Spatafore, adds, "James is one guy who never turned his back on me. He was the most humble and gifted actor and person I have ever worked with. He was a great man and I will forever be indebted to him", while Steve Schirripa, The Sopranos' Bobby Baccalieri, says, "Jimmy was a dear friend and like a brother to me. He was a great actor and a great father. I will miss him terribly. I am very sad."
Edie Falco, who played Gandolfini's onscreen wife, has yet to comment on the tragedy.
The Sopranos ran for six seasons between 1999 and 2007.