On Her Birthday, a Look at How Sienna Miller Mastered Modern Boho Style

Sienna Miller has long been a master of boho style. Her love of a romantic, free-spirited fashion aesthetic traces all the way back to the 2000s, when she was known to traipse around music festivals like Coachella and Glastonbury wearing studded Chloé boots and vintage vests.

Even two decades later (and on her 44th birthday today), Miller is still proving a devotee to bohemian staples like ruffles, lace, and maxi dresses—and her love of the whimsical couldn’t come at a better time. With labels like Chloé and Valentino leaning into the frilly sensibility this year, simply nobody is doing modern-day boho dressing better than her.

The American-British star has been reviving the look over the past year. It all began when Miller attended the fall 2024 Chloé debut of designer Chemena Kamali, who is also largely to thank for re-igniting the boho trend. Miller hit the front row in the label’s black leather bomber jacket and white silk-lace skirt. “It was the most beautiful show I’ve seen in a long time,” Miller told Vogue at the time. “It was like my dream wardrobe walking past me.” It’s no wonder: The lace maxi dresses and billowy fabrics seemed to be plucked right out of her 2000s closet.

Once fashion fell in love with look again, it didn’t take long for Miller to reclaim the early aughts trend. Almost every red carpet she has hit since—whether at the Met Gala, or while promoting Horizon—she has continued the look, doubling down on Chloé’s elegant, soft, and feminine designs.

At the 2025 Fashion Awards wearing Givenchy by Sarah BurtonPhoto: Getty Images

Take her appearance at the 2024 Met Gala, when she graced the Met steps in a white lace maxi dress from the label—a heavenly construction. Or when she attended the closing ceremony of the Venice Film Festival wearing a sheer white lace dress, punctuated with leather thigh-high boots and an oversized Chloé belt. On anyone else, the look—directly plucked from the runway—could read literal or even lazy, yet on Miller, it seemed totally appropriate. A look she would wear, say on, a regular Tuesday.

Miller’s love of bohemian style has also extended to everyday separates, too. For the spring 2025 Chloé show, she leaned into pastels with a blue draped jacket and pink high-waisted trousers. For the 2025 Fashion Awards in London, she also stepped out in a gauzy, white tulle gown from Givenchy by Sarah Burton. Whether dressed up or down, Miller has perfectly captured the essence of boho dressing—which is to never look like you are trying too hard. That skill is precisely why she will always be the queen of boho style, and we predict it’s here to stay come 2026.

Below, explore some of Miller’s best boho style moments this year.