Since the news, famous friends, co-stars and admirers have gone to tweet their condolences for the fallen star.
Alyssa Milano: "Rest in peace, Mr. Gandolfini."
Brooke Burke: "Life is way too short & precious. So sad to hear of James Gandolfini passing 2day. Prayers for him &his loved ones. So sad at young 51"
Lance Bass: "So so so sad about James Gandolfini - 51 is way too young."
Jerry Ferrera: "Rip James Gandolfini. One of the greatest actors of our generation."
Ralph Macchio: "RIP James Gandolfini. Terrible news."
B.J. Novak: "James Gandolfini on "Inside The Actors Studio": one of the most inspiring interviews about acting I have ever seen."
Sophia Bush: "So, so sad. A huge loss for storytellers..."
Ewan McGregor: "Jesus. The world just lost one of its great actors. James Gandolfini has passed away. Thoughts to his family. Such a talent. I'm saddened."
Octavia Spencer: "RIP James Gandolfini. So sad!!"
Bethenny Frankel: "Just heard TV icon James Gandolfini has died. I'm shocked. I'm sad. I loved his work. My heart goes out to his family."
Leah Remini: "R.I.P James Gandolfini. My prayers to his family and friends. He will certainly be missed by us who loved watching him"
Pauly D: "Wow RIP #JamesGandolfini !!!! My Favorite Show Of All Time The Sopranos , My Heart And Prayers Go Out To Your Loved Ones"
Lucy Hale: "So sad to hear about James Gandolfini. RIP"
Jonah Hill: "I'm truly heartbroken to hear that James Gandolfini has passed away. He is one of my all time favorite actors. Tragic loss."
Russell Simmons: "Not tony soprano! Damn. Such a good guy and a great actor. James, rest in peace..."
Richard Roeper: "Hard to believe Mr. Gandolfini was just 37 when "The Sopranos" premiered. Gone way too soon at 51."
Rose McGowan: "I am heartbroken about James Gandolfini. He was a gentle giant and great man. I love this picture, I loved him."
Wayne Brady: "RIP James Gandolfini...51 yrs old. So sad."
Johnny Knoxville: "James Gandolfini RIP. xo"
Carson Daly: "SO SAD! PRAYING FOR HIS FAMILY- wow- Shocked by this news today...."
Rob Lowe: "James Gandoldini gave the greatest performance in the history of television. He was also a kind man. Condolences to his family."
Piers Morgan: "Amazing outpouring of tributes to James Gandolfini - reflective of the huge impact he had as Tony Soprano, one of TV's greatest characters."
Christina Applegate: "I am so deeply saddened by the untimely passing of sweet James Gandolfini! My heart is broken for his family!! I'm in shock"
Steve Carell: "James Gandolfini. What a great loss."
Olivia Wilde: "James Gandolfini was a kind, funny, wonderful guy. I'm so lucky to have worked with him. Sending love to his family. Such a sad, sad day."
Rainn Wilson: "Arrivederci, James Gandolfini. You were one of the great greats. We'll miss your dangerous, big heart. #RIPGandolfini"
Melissa Joan Hart: "Just saw the news and what a loss! #RIP James Gandolfini"
--Reporting by Lindsey Caldwell