Rooney Mara burst onto our fashion radar when she played Lisbeth Salander in The Girl With A Dragon Tattoo, and had a brutal transformation with her hair dyed black, eyebrows bleached and lots of piercings. Rooney embraced her dramatic new look and changed from a girl next door with tumbling long hair to uber-sleek striking dresser, with a statement black fringe and red red lips.

The actress, who has also starred in The Social Network, became hot fashion property in 2012 on her mammouth promotional tour of The Girl With A Dragon Tattoo. January 2012 was pretty much Rooney Mara month, as every day brought a new premiere, a new Givenchy or other luxe label gown and a fresh dose of Rooney Mara wardrobe envy. 

Rooney stands out a mile in Hollywood, as her style is unique, edgy and unlike the usual frothy sparkly creations we usually see in Awards season. It was certainly recognised by the fashion industry as she was a magazine cover regular in 2012, including appearing on the W Magazine special anniversary cover with Keira Knightley, Scarlett Johansson and Mia Wasikowska.

Rooney is the queen of minimal dressing, but that doesn't mean she's boring. Her emphasis is always on structure and silhouette, oh and a good dark lipstick. She made us all fall for cut-outs, as her dresses usually include at least one, such as the plunging Nina Ricci gown she wore to the 2012 Golden Globe Awards.

You won't catch Rooney in layered necklaces or stacked bangles, and she rarely carries a clutch. She is allergic to embellishment, wears little makeup (other than the lippie) and she usually opts for classic black shoes. Her focus is always on the clothes, or should we say the couture. You'll also rarely see Rooney in colour, as she sticks to black or white and the occassional splash of red. She always wows in winter white, such as the whiter than white Givenchy Couture gowns she wore to the London and Tokyo premieres of The Girl With A Dragon Tattoo in a freezing December and January.

With her striking signature style we think Rooney Mara will be one of our style icons for a long, long time. Take a look through the gallery above to see Rooney's dramatic style evolution...