On Vogue.com, Barbie A Style Icon, in Dior and a number of other designer duds.
That would be the famous Dior "Bar" suit.
From the V&A-The Golden Age of Couture:
'Bar' is one of the most important designs from Dior’s first collection. The tight-fitting jacket has padded hips which emphasise the tiny waist. The long pleated wool skirt, backed with cambric, is exceptionally heavy.