'Cheers' Star George Wendt Dead at 76

George Wendt, famous for his starring role in the long-running NBC sitcom "Cheers," is dead.

Family sources tell TMZ ... he died early Tuesday morning, passing peacefully in his sleep at his home.

The official cause of death is unclear.

George's family is remembering him as "a doting family man, a well-loved friend and confidant to all of those lucky enough to have known him" ... and they say he will be missed forever.

Wendt starred as Norm Peterson in all 275 episodes of "Cheers" and earned six consecutive nominations for the Primetime Emmy Award for outstanding supporting actor in a comedy series.

When "Cheers" went off the air in 1993, George got his own sitcom, "The George Wendt Show."

George also acted on the big screen ... with roles in "Airplane II: The Sequel," "No Small Affair," "Fletch," "The Little Rascals," "Spice World," "Outside Providence," "Alice in Wonderland," "Santa Buddies" and "Sandy Wexler."

He was born in Chicago as one of nine children and went to high school in Prairie du Chien, Wisconsin before enrolling at the University of Notre Dame. After college, he got into sketch comedy improv and landed a few small roles on TV shows like "Taxi," "Soap," and "M*A*S*H" ... before getting his big break on "Cheers."

George was 76.