Helen Mirren is backing into Buckingham again. It’s her third shot.

2006 she won an Oscar for playing Her Maj, sovereign of England, Scotland, Wales and parts of Ireland, a k a the mother-in-law of Prince William’s pregnant Duchess Catherine of Cambridge a k a Kate Middleton.

She pranced around in a two-part HBO thing called “Elizabeth I,” for which she copped not a tiara but an Emmy.

Helen Mirren is not just any broad. She’s a Dame. And now, her husband, director Taylor Hackford, told me: “Can you believe it? I can’t believe it. She’s again playing the Queen.

“It’s onstage. A play called ‘The Audience,’ which opens at the Gielgud Theatre in London’s West End. Peter Morgan, who wrote that film for which she won the Oscar, wrote it. Three-time Academy Award nominee Stephen Daldry (“The Reader,” “Billy Elliot”) is directing. It’s about the Queen’s private once weekly meetings with her 12 prime ministers over 60 years.”

In actuality, these sessions remain private. Nothing’s ever repeated. You can’t mention them even in your sleep. Sometimes they’re personal, ofttimes confrontational. This script imagines what transpires between Downing Street and the Palace, between the revolving PMs and the one constant Majesty.

Per Dame Helen: “It’s about people — these PMs and this one woman — handling power. As a young unknowledgeable sovereign, she’s nervous. As she progresses they become the nervous ones.”

“The Audience” opens in March.

SUNDAY Feb. 10 is the Grammys 54th edition. Forget Beyoncé’s tonsils, Timberlake’s wardrobe or which Cub Scouts Taylor Swift’s songs will immortalize. The 22-karat invite’s the night before at the Beverly Hilton, where Grand Pasha Clive Davis gives his invitation-only party. Movie, TV, music and sports hotshots show. So damn exclusive that I doubt even the Queen could crash. Harry, yes; the Queen, iffy.

That night L.A. Reid gets the Icon Award. Presenter is National Academy of Recording Arts and Sciences’ Neil Portnow. And CBS’s Leslie Moonves will introduce Clive.

THIS evening. Park Avenue Armory. The Young Collectors Night at the Winter Antiques Show. Nate Berkus is showing stuff. And strutting around will be the mayor’s longtime designer Jamie Drake, who’ll discuss design/fine art/culture with the junior collectors and philanthropists. I think this might interest the Queen. Harry, not.

SPEAKING of Hizzoner, he’ll be lampooned big-time at March 23’s Inner Circle. Rehearsals already began. He’ll rebut while performing with an existing Broadway show . . . Watch for a virus that might infect your computer. The Mike Tyson virus. Quits after two bytes . . . From a Little Rock eatery, Hillary’s favorite dessert’s Pinnacle Mountain Pie: mocha ice cream, hot fudge, Kahlua, whipped cream, strawberries, Oreo cookie crust.

UMA — ask not Uma who? There exists no such person as Uma Leibowitz. Anyway, she has a controversial role in Danish avant-garde director Lars von Trier’s coming movie with the lovely title “Nymphomaniac.” A musical this isn’t. It co-stars Shia LaBeouf, who in this job shows just how beouf he is. Full-frontal hangs out.

In the editing room as we speak, this charming controversial film should shpritz out in May. In it, Uma does a monologue, but there’s footage of whatever Shia’s doing. While they’re excited to excite the fans, a decision’s now being made as to how much to show and how often.

It’s said Shia’s said: “I didn’t become an actor to become a porn star.”

THIS week at Lincoln Center, pianist Lola Astanova’s Tchaikovsky and Rachmaninoff were almost outglitzed by Catherine Malandrino’s metallic wrap dress, Louboutin shoes and Helen Yarmak borrowed diamonds . . . Rep. Carolyn Maloney signed autographs and posed for pix at 32nd and Second’s TD Bank . . . James Caan hanging at an Aventura, Fla., cigar bar?

UNLIKE its married owners, our famous Carnegie Deli’s going great. The divorced Mrs. Sandy Levine may have closed the husband out but not the deli. Definitely staying open is NYC’s beloved Carnegie . . . “The Scroll: Evidence of Life Unseen,” faith-based testimonials featuring Al Sharpton, runs Sunday on Magic Johnson’s ASPiRE network . . . Syndicated Steve Harvey, renewed for another year, shriveled 21 pounds in 21 days on Dr. Roni DeLuz and James Hester’s “1 Pound a Day: Martha’s Vineyard Diet Detox,” out March 26.

DAVID Zimmerman, who owns Sammy’s Roumanian on Chrystie Street, just became a daddy. It’s a boy. In thanks, he sent nurses at St. Barnabas Medical Center a crate of chopped liver.

Only in New York, kids, only in New York.