She's known for her trend-setting style and unique sense of fashion.

So when Sienna Miller stepped out last night with a chic new hairstyle at the launch party for the collaboration between Matthew Williamson and Belevedere Vodka, she undoubtedly prompted thousands of fans to dash to the hairdressers.

With a thick fringe and choppy layers, the new style framed Sienna's face perfectly.

New 'do: Sienna Miller unveiled her new hairstyle, complete with a fringe, at a launch party last night

Sienna, 28,has tried a variety of styles since first stepping into the spotlight in 2001, including the loose, boho waves she is famous for.

She has also tried a choppy bob and gamine crop, but has now returned to her favourite style with one addition - a fringe.

And whether it's a night look, or a day look, Sienna's new 'do works perfectly with whatever she wears.

Nighttime glamour: Sienna looked stunning in a metallic minidress at the launch party for the collaboration between Matthew Williamson and Belevedere Vodka

What would Jude say? Sienna can't hide her affection for designer Matthew Williamson at the launch

Just hours after stepping out in a metallic minidress at a the launch party, Sienna arrived at the Chelsea Flower Show in a chic Breton Stripe t-shirt, skinny jeans and red pixie-style boots.

She also added a red Prada handbag and mirrored aviator sunglasses for good measure.

But Sienna's most noticeable accessory was her beaming smile, which stayed on her face for the majority of the day.

Chic: Sienna looked stylish in a Breton Stripe t-shirt, skinny jeans and red pixie-style boots at the Chelsea Flower Show in London today

Casual: Sienna accessorised her outfit with aviator sunglasses, a Prada handbag and a beaming smile

The reason for the smile could be the fact she recently reconciled with ex-boyfriend Jude Law.

The pair are even said to be considering getting married in Gloucestershire this summer, with a friend saying: 'They don’t want to jinx things by talking about it, but they have told their nearest and dearest that they would like to get married in the summer.'

While Sienna has become known as a fashion icon, the actress says she wants to be known for her professional capabilites rather than the clothes she wears.

Reclining: Sienna sits back as she takes a breather from the horticultural event

She said recently: 'I desperately want to be seen as something other than someone who just wears clothes.

'This whole fashion thing is not anything I've wanted particularly. People think I wear nice stuff. That is lovely and flattering but not important.

'I have always collected vintage clothes. I love the smell of old material just from being a little girl when I enjoyed dressing up.'

Regardless of her opinion of her fashion icon status, Sienna has quickly secured her place as a respected designer after starting fashion label Twenty8Twelve with sister Savannah.