Margot Robbie‘s fantabulously emancipating her famous posterior … wearing a dress so sheer her entire backside was on display while she walked the red carpet!

The actress hit the “A Big Bold Beautiful Journey” premiere in the United Kingdom Thursday … and, when she turned around, we got an eyeful of her ‘Bombshell’ bottom.

Ya gotta see the pics for yourself … Margot’s glittering from chest to toes in a sparkling dress — with jewels obscuring the otherwise completely sheer fabric.

We can’t see everything Margot’s workin’ with … but, we can see a whole lot — including a hint of the thong that’s doing nothing to cover her up.

She’s also sporting a whole lotta sideboob … clearly not wearing a bra in this outfit — and, we’re sure it got one or two overexcited people Wolf (of Wall Street) whistling at the A-lister.

Robbie stars in “A Big Bold Beautiful Journey” with Colin Farrell … which is rated R, BTW. However, that seems mainly because of strong language — don’t expect Margot to gallivant around in a dress like this in the flick! The new movie marks Margot’s first release since “Barbie” — and since becoming a new mom!