Following the unexpected news of actor James Galdofini's death at the age of 51, tributes have been pouring in from Hollywood.

The Sopranos star passed away after suffering a suspected heart attack while holidaying in Italy.

His fellow actors and fans of his work shared their shock and grief over his passing on their Twitter pages.

The Office star Steve Carell wrote: "James Gandolfini. Unbelievably sad news. A fine man."

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."

Director and actor Jon Favreau: "Sad over the news about Gandolfini. Such a shock."

Man of Steel's Russel Crowe: "Sad to hear about James Gandolfini. First met Jimmy back in '94.He was roommates in NY with Lenny Loftin. Lovely man. RIP Jimmy"

Samuel L Jackson: "Massive blow to the acting community today... The passing of James Gandolfini. So talented. My heart goes out to his family!"

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."

Ricky Gervais: "Damn. RIP James Gandofini. An amazing actor that made arguably the greatest drama of all time, & a funny, sweet, gentle giant off screen."

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."

Debra Messing: "Heartbreaking news about James Gandolfini... Shocking. HUGE loss. Kind, humble, and a Singular Talent. Rest in Peace."

Susan Sarandon: "So sad to lose James Gandolfini. One of the sweetest, funniest, most generous actors I’ve ever worked with. Sending prayers to his family."

John Cusack: "RIP James Gandolfini - had the pleasure of working with him and knowing him a bit- always a truth teller- gent and all around class act."

Justin Timberlake: "Really though... This James Gandolfini passing is so sad. My heart goes out to his family in this time. RIP #takentoosoon"