Stunning in a floor length black Alexander McQueen gown and elbow length black gloves, teamed with the iconic updo, it turns out Gaga's Hepburn's resemblance was no accident.
The A Star Is Born front woman, who's up for two Oscars, wore a beautiful 128.54 carat necklace that was last worn by Hepburn herself in 1962.
Made by Tiffany & Co, the Tiffany Diamond was last worn by the actress when she was promoting her iconic film, Breakfast at Tiffany's.
No one except Gaga has worn the incredible piece since Hepburn, but it does look slightly different from its original appearance all those years ago.
The necklace has been altered to feel a little more modern as Gaga teams it with yellow diamond earrings to match - although you can understand our disappointment that she opted not to add a tiara in the mix too.
Tonight is the first time the stunning piece of jewelry has made its way onto a red carpet, and we couldn't think of anyone more deserving to give the necklace its Oscars debut.
It's hardly surprising the necklace hasn't had more outings as it's thought to be worth several millions of pounds as it was worth an impressive $5 million back in the sixties, which would equate to around $30 million today. Wow, that's a lot to be carrying around your neck.
Tiffany & Co's artistic officer, Reed Krackoff said: "Lady Gaga is the ultimate creator, innovator and rule breaker, and I'm thrilled that she will be wearing the legendary Tiffany Diamond on the awards show red carpet for the first time since it was discovered 141 years ago."
Sandra Amador and Tom Eerebout, Lady Gaga's stylists, added: "The chance to work with such an amazing piece of design and history tonight is a creative dream come true.
"There are so many beautiful jewels in the world, but the radiant Tiffany Diamond, which weighs over 128 carats, is truly exceptional, which is just so fitting for Lady Gaga."