Sienna Miller worked 70s chic as she left the Royal Haymarket Theatre. Photo: Rex
Sienna also recently launched her clothing collection Twenty8Twelve at Selfridges - so she's got a lot to smile about!
What do you think of Sienna's shaggy goat? Yay or nay?
The Perfect 10: Sienna Miller
Is this Sienna's best red carpet moment to date? She looked stunning in a backless Matthew Williamson gown at the Baftas 2007.
The Factory Girl opted for another backless number at the 2008 Bafta Awards - a slinky Dior gown, to be precise, paired with Chopard jewels.
Sienna Miller wowed in red at the Valentino 45th Anniversary celebration, back in July 2007. The gown? Valentino natch!
The Layer Cake actress was pretty in pink in this strapless number at the Montblanc Signature for Good Charity event in 2009.
She wore her favourite designer, Matthew Williamson, to pick up her award for Elle Style Icon in 2009.
Miller looked radiant on the red carpet at the opening of the House of Esquire in LA in this navy cocktail dress. Going blue instead of basic black played perfectly with her icy eyes.
The star of GI Joe oozed Hollywood glamour in this gold gown teamed with ruby red lips and curled locks.
Sienna sparkled in a Swarovski embellished mini dress from her own Twenty8Twelve collection to the 2009 MTV Movie Awards.
Sienna Miller on the red carpet with Jude Law at the 2010 MET Ball. With her main man back on her arm she dazzled in a low-cut Pucci gown.
The star looked gorgeous in a nude, Stella McCartney gown at the Unesco Charity Gala in October 2010.