Leonardo DiCaprio, Kate Moss and pals enjoy VIP dinner at Carbone London ahead of official opening

The environmentalist left a Carbone footprint.

Leonardo DiCaprio had a private dinner with Kate Moss, Sean Penn, Benicio del Toro and Tobey Maguire at Carbone London — days before the restaurant officially opened to the public, Page Six has exclusively learned.

A source confirmed that DiCaprio and his A-list pals “slipped in for a sneak peek of the restaurant” on Monday night ahead of the Italian eatery’s official launch in London’s buzzy Mayfair neighborhood.

They were “all dining together” and went “unnoticed,” the source said of the Hollywood heavyhitters, adding that the group was “super discreet.”

The “Titanic” star, 50, and his famous friends enjoyed a preview of Major Food Group’s new menu featuring classic dishes like Spicy Rigatoni Vodka, Veal Parmesan and tableside-prepared Caesar salad, as well as new recipes created exclusively for the London location.

DiCaprio, Penn, and del Toro are co-stars in the upcoming film, “One Battle After Another,” which premieres next Friday.

Meanwhile, DiCaprio and Maguire are childhood friends, while the Oscar winner’s friendship with Moss dates back to the early ’90s.

We hear the London spot officially opened with a star-studded soirée Tuesday night.

Major Food Group co-founders Chef Mario Carbone and Jeff Zalaznick were there to welcome a glittering crowd, including actress Minnie Driver and Universal Music Group Chairman & CEO Sir Lucian Grainge.

Also spotted at the party were hotelier André Balazs, billionaire Lucy Guo, and Authentic Brands Group founder Jamie Salter.

“Jeff Zalaznick welcomed the room with a speech before guests raised glasses of Barolo to toast the group’s first UK outpost,” the insider shared.

We’re told the foodie fête featured moody lighting and towering florals that complemented the beautiful dining room’s interiors, which were dreamed up by design visionary Ken Fulk.

The hotly anticipated restaurant officially began taking reservations Wednesday night.

Carbone — which first debuted in Manhattan’s Greenwich Village — already has locations in Las Vegas, Miami and Dallas as well as Hong Kong, Doha, Riyadh and Dubai.