Musso & Frank Grill has catered to Hollywood players for 100 years and the venerable establishment is celebrating its centennial anniversary on Sept. 27. A book about the restaurant will be released. The Hollywood Award of Excellence, the first of its kind for a restaurant, will be presented by the Hollywood Chamber of Commerce.

Musso’s is also expanding, with three new private dining rooms set to open in early 2020.

“Our family and the Hollywood community can’t even measure the historic importance of the restaurant reaching its 100th anniversary,” says COO-CFO-proprietor and fourth-generation owner Mark Echeverria. “We’re so proud of the entire team and what the generations before us did. It’s an unbelievable milestone.

“We grew up with Hollywood. In 1919, Hollywood Boulevard was a dirt road and the industry was just starting to take off.”

When Musso & Frank opened its doors on the now iconic boulevard in 1919, it was in the center of a new universe: cinema entrepreneurs such as Charlie Chaplin (whose studio was on nearby La Brea Avenue), the Cohns (it would take a few years before they established Columbia), Adolph Zukor (at Paramount), Mack Sennett and others were inventing the film industry.

Fledgling studios, rehearsal spaces, acting schools, radio stations, record companies — Capitol Records is right around the corner — and later TV studios and broadcasters were all clustered around the heart of Hollywood, so Musso’s became the place for a quick bite between a radio gig and acting class, or a studio meeting and an audition.

Chaplin used to ride his horse to Musso’s for his favorite lunch of grilled lamb kidneys with bacon prepared by Musso’s first executive chef, Jean Rue, who presided as lord of the kitchen for more than 50 years. The food and cocktails — such as the all-important martini — were draws, but the restaurant also offered a clubby atmosphere away from the ingenues and flashbulbs of glitzier places in town.

Musso’s has been a favorite of everyone from Marilyn Monroe to Johnny Depp to Orson Welles to Keith Richards — even mobsters Bugsy Siegel and Mickey Cohen called it home.

Musso’s became a writers’ hangout, mainly because it was across the street from the Writers Guild of America. William Faulkner, Raymond Chandler, William Saroyan, Dorothy Parker, Charles Bukowski, Lillian Hellman and the literary giants that called Musso’s a second home.

Recently, Quentin Tarantino’s “Once Upon a Time … in Hollywood,” set in 1969, used the eatery as a character, an elegy for a neighborhood that has morphed into something different. “We’re always excited to be a part of movies, but we’re a restaurant first,” says Echeverria. “We’re very selective about the movies and television shows [that] have featured us and have shot on the premises. When Quentin approached us, he wanted to shut the restaurant down for five days, and normally, we limit filming to Mondays when we’re dark. But we’ve known Quentin for a long time and we knew he’d present us in a great way.”

Musso’s began its screen career in 1922, with an appearance in Buster Keaton’s “Cop.” In productions such as “Ed Wood,” “Swingers,” “Ocean’s Eleven,” “Ray Donovan,” “Mad Men” and “The Kominsky Method,” Musso’s is used as shorthand for the Hollywood insider.

And while bold-face names made the restaurant famous, some of its employees also enjoy a level of fame. Bartender Ruben Rueda and waiter Sergio Gonzalez were decades-long employees, men who created distinct connections with both Hollywood royalty and regular diners. They died within days of each other earlier this year, with Gonzalez passing away the night he came home from Rueda’s memorial service.

“Each generation has brought a tremendous sense of enthusiasm and passion to Musso’s,” says Echeverria. “Don’t try and reinvent the wheel. Stay humble and work with smart people. And treat everyone like family. ”