Sienna Miller's Street Style Evolution

L'OFFICIEL's Spring 2021 cover star's street style moments chart her ever-evolving look, from boho chic to smart sets.

Spring 2021 L'OFFICIEL cover star Sienna Miller has style tips to dispense for years to come. The American-born, British-raised actress, who has inaugurated—and ended—fashion trends her whole life, is a contemporary style icon. From trademarking boho fashion with flowy dresses, floppy hats, wide belts, and cowboy boots to making a case for casual outfits when many A-listers were still dressing up in posh clothes for red carpet events, Miller defined the noughties with her effortlessly chic Brit poise and blonde beachy hair. Here, L'OFFICIEL maps out the actress' street style evolution with some of her best looks from the past two decades.

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Miller at the Nick Harvey Society Archive in London in 2003 rocking the dress-over-jeans look of Y2K.

Miller at the "Keen Eddie" premiere in May 2003 wearing her mother’s vintage Missoni dress from the ’70s, and an old chain.

The actress is photographed donning a Marc Jacobs green dress with a mini black Balenciaga city bag in 2004.

Miller rocks a cool groupie look with leather cowboy boots and short denim mini skirt at Glastonbury Festival in 2004.

Miller with ex-partner and actor Jude Law wearing a fur jacket and leopard print bag in 2004.

At her sister Savannah’s wedding in Devon in 2005, Sienna wears a vintage boho-style floral midi dress.

The actress is pictured leaving Gerry’s in London back in 2005 in a total black look.

Miller at the after party for "Factory Girl" in New York, channeling '60s-style vibes with a mohair jumper and dark eyeliner.

A pregnant Miller is seen with a boho flowy dress during a stroll through her Primrose Hill neighborhood in 2012.

Miller sports a pair of baggy boyfriend jeans, a mustard fedora hat, and a yellow Rachel Pally crop-top for one of her city outings in 2013.

In 2016, Miller styles black leather shorts and a white tee with tights, booties, and a tweed Chanel jacket.

Out and about in New York City in 2017, the celebrity opts for a casual wide leg pants and sweater over tee look.

Chic yet sporty, Miller wears her usual black jeans, a navy T-shirt, and black loafers with a pop of color with a red, green, and navy patchwork Gucci leather jacket from the men's department.

Miller looks super polished in a Ralph Lauren tan double breasted blazer with matching straight-fit trousers while attending the 2019 Wimbledon Tennis Championships.

Looking very festive, Miller stuns in a green sequin dress as she leads glamour at Noel Gallagher's Christmas bash in 2019.

The British actress looks stunning in an emerald green Gucci suit while out and about in New York City in 2019.

The "American Woman" star is bundled up against the chill in Gucci’s Fria GG woolly ankle boots, a calf-skimming marble grey fleece coat paired with a matching grey sweater, and a pair of leopard print leggings.

Miller shows her effortless style in a blue pinstriped longline coat with a pair of Gucci trainers and a white crossover handbag.

Mixing style with comfort, Miller walks the city streets with her fiancé and daughter Marlowe in a tie-dye purple midi dress paired with a large brown handbag and a pair of white sneakers.

Miller turns her scarf into a two-in-one accessory, adding a touch of color to her otherwise neutral outfit consisting of a white tank, high-waisted khaki pants by Mango, printed Gucci sneakers, and an oversized Proenza Schouler bucket bag.