The actress' big skirted frock reminded us a bit of those Big Fat Gypsy Weddings creations *giggles*
[Related article: Michelle Williams on being sexy]
However, Michelle's gown was not made by Thelma but in fact Dior, who sponsored the whole event.
Marilyn was a fan of the fashion house, and features in their new J'Adore Dior perfume ad.
Michelle's big pink puffball was quite the about turn from her sleek monochrome BAFTAs choice.
That slinky number was by high street fave H&M, but it was bespoke rather than off the peg.
[Related gallery: BAFTA 2012 red carpet fashion]
Although we can't get our hands on that particular number, Grazia reports we will be able to get a piece of the action. It has inspired a top and skirt in the latest H&M conscious collection, out in April.