Oscar-nominated for the third time, take a look back at the star's career moments
What: My Week With Marilyn
Williams tackled her biggest challenge to date when she transformed into Hollywood screen legend Marilyn Monroe. The role has garnered her a Golden Globe award and a Best Actress Oscar nomination - and we're convinced it's helped shape her enviable off-screen style.
What: Meek's Cutoff
The actress hit the Oregon trail circa 1845 in this Western indie flick directed by Kelly Reichardt.
What: Blue Valentine
The indie darling earned her first Best Actress Academy Award nomination for her portrayal of exasperated wife Cindy opposite Ryan Gosling in Blue Valentine.
What: Shutter Island
The actress was handpicked by director Martin Scorcese to play the role of Leonardo DiCaprio's deceased - but all too present - wife in this psychological thriller.
Williams played the female lead - a seductress named 'S' - in this thriller with Ewan McGregor and Hugh Jackman.
What: Wendy and Lucy
Proving her acting talents in indie director Kelly Reichardt's melancholy film about a girl who experiences a series of setbacks, Williams shows that she doesn't need a full face of war paint and a stylish coif to hold an audience captive.
What: Brokeback Mountain
Williams met her future partner and father of her daughter, Matilda, on the set of Ang Lee's provocative film about two cowboys who pursue a forbidden love affair. Her role as Ledger's on-screen wife, Alma, also earned her a Best Supporting Actress nomination from the Academy.
What: I'm Not There
The star's supporting role as Coco Rivington in this film, where six different actors play Bob Dylan, wasn't her most memorable on-screen acting moment, but her take on swinging sixties style is pitch-perfect.
What: Land of Plenty
Director Wim Wenders cast Williams as Lana in this exploration of post-9/11 malaise.
What: A Hole in One
In this quirky flick, Williams played a 1950s suburban girl who starts to question her sanity... and decides she wants a lobotomy. Things aren't all bad - that net veil is divine.
What: The Station Agent
The actress played a librarian opposite Peter Dinklage in this BAFTA-winning indie flick.
What: Prozac Nation
Williams starred opposite Christina Ricci as Harvard pal Ruby in this exploration of depression and drug abuse based on Elizabeth Wurtzel's acclaimed book.
What: Me Without You
Williams tries her hand at a British accent as we see her play Brighton girl Holly, and witness the trials and tribulations she goes through with best friend Marina (played by Anna Friel).
What: Halloween H2O: 20 Years Later
Williams made the leap from small to big screen with a role in this slasher flick, where she mastered the art of screaming in fear. Who would have known it would be the start of such a rich and lauded film career?
What: Dawson's Creek
The actress made her small screen debut playing girl-with-a-past Jen as one of the key quartet - alongside Katie Holmes, James Van Der Beek and Joshua Jackson - on this hit teen show chronicling four friends and their relationships.