And it's all thanks to her new winning formula...
Thanks to the endless magic of layering, Julia's fondness for a trouser-beneath-the-dress situation has not only seen her slaying best dressed lists globally, but also proving the trend isn't solely for lazy days in the office when the weather's doing that annoying 'transitional' thing.
Nailing the look in both Stella McCartney (Globes) and Louis Vuitton (Critics' Choice), Julia elevated the trend with beautifully tailored trousers and clever use of fabrication.
And while the actress may be our current must for the #lewk, she's not the only one to nail the look for a black-tie occasion.
Fellow actress Emma Watson is one of the trend's key pioneers, and most memorably wore *that* red Dior dress over black cigarette trousers at the 2014 Golden Globes.
A trend that went mainstream early last year, the dress-over-trousers look is one that thrilled every office-dweller in the land, thanks to both its versatility and the endlessly-flattering silhouette it creates.
But, for those who have had their finger on the pulse for longer than a quick minute, the layered look is no new thing. Launched into popular culture via the likes of B*Witched & pals, it's yet another trend that because of which we owe thanks to the nineties.
Here are the 10 things we'll *all* be wearing in 2019
Scroll down to see the other huge trends that will dominate your Instagram feeds this year...