You can pretty much guarantee that where Sienna Miller leads, I will follow, and never has that felt quite so true as this week, when I spotted the actor stepping out in London in one of the chicest pairs of black knee-high boots I've seen this season. Crucially, she opted for a flat pair rather than a heeled style—a silhouette that's surprisingly hard to find a truly elegant iteration of. Her choice? A glossy black leather pair from British high-street favourite Dune. With a sleek, chisel-toe finish and an elongated design that reaches the knee, these boots brought a sophisticated feel straight to the foundation of her look.

Finding a flat knee-high boot that feels genuinely elegant isn't always easy. Too often, the options that catch my eye come with a heel, making them far less practical for everyday wear. Sienna's pair retains all of the poise of a heeled boot, with a slim sole and sleek design, yet with none of the discomfort of being propped up on the balls of your feet.

(Image credit: Getty Images)

Styling hers with black tailored knee-length shorts, the pairing left just a sliver of skin between the hem and the top of the boots, bringing a lightness to the outfit that felt balanced against the navy knit she paired it with. A woven handbag sat in her grip, and dark sunglasses framed her eyes, giving me a chic autumn outfit I'll be drawing inspiration from throughout these milder days.

Whilst Sienna's boots proved the perfect pairing for her knee-length shorts, I'd wear them just as readily with a knee-length or longer skirt. Then, come winter, they'll offer an extra layer of warmth beneath longer trousers or even tucked into jeans.

Priced at £189, Dune's Leather Knee-High Boots won't stay in stock for long. If you're looking to invest in a pair of flat knee-high boots this season, read on to shop Miller's exact pair, alongside my edit of the best styles on the market right now.

Shop Sienna's Boots:

Dune London Toova - Black

Shop Flat Knee-High Boots:

Reformation Remy Flat Knee Boot

This also comes in brown suede and snake print.

Massimo Dutti Leather Riding Boots

Just watch: riding boots will be one of the biggest shoe trends of the winter.

Mango Leather High Boots | Mango United Kingdom

Wear these with tailored shorts or tuck them into jeans.

Nobodys Child Black Leather Knee High Boots

Every great wardrobe starts with a pair of knee-high boots.

H&M Knee-High Boots

Be quick! This won't stay in stock for long.

Anonymous Copenhagen Valle 20 Soft Calf Black

This also comes in 18 other shades.

ZARA Stretch Flat Knee-High Boots

The sock boot trend isn't showing any signs of slowing down.

Sezane Bridget Knee Boots

You'll come back to these boots every single autumn.