Tennis whites. Photo:Dave M.Bennett/Getty Images
Sienna Miller joined a host of tennis fans at a Ralph Lauren dress.
Ms Miller teamed her high-neck frock with chunky ankle boots, a black long-strap handbag, scraped back ponytail and bold lip.
Sienna was joined by sister Savannah and mum Jo Miller at the event, held at the Ralph Lauren store on Brompton Road.
Ralph Lauren have this year continued their collaboration as Wimbledon's official outfitters to celebrate the 125th anniversary of the tennis tournament.
What do you think of Sienna's tennis whites? Let us know in a comment below.
The Perfect 10: Sienna Miller
Is this Sienna's best red carpet moment to date? She looks stunning in a backless Matthew Williamson gown at the Baftas 2007.
The Factory Girl opted for another backless number at the 2008 Bafta Awards. This time she opted for a slinky Dior gown and Chopard jewels.
Sienna Miller wows in red at the Valentino 45th Anniversary celebration, back in July 2007. She opted for a spectacular Valentino gown, of course.
The Layer Cake actress looked 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.
The perfect LBD! Miller looks radiant on the red carpet at the opening of the House of Esquire in LA.
The star of GI Joe arrives at a screening for the movie in LA. Sienna 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. Sienna dazzled in a low-cut Pucci gown.
The Alfie star looked gorgeous in a nude, Stella McCartney gown at the Unesco Charity Gala in October 2010. She can't keep away from that red lipstick!