Sienna Miller’s Cult High-Street Trench Coat Sells Out Every Single Year—So I Finally Tried It On

The elegant Sézane Clyde trench coat has amassed a celebrity fanbase. Now, it's back for autumn.

By Kim BrowneSeptember 5, 2026

Sienna Miller’s Cult High-Street Trench Coat Sells Out Every Single Year—So I Finally Tried It On

There’s no singular wardrobe item that embodies autumn quite like a trench coat. As the leaves start to fall and temperatures begin to call for more than a light tee and jeans, my first port of call is always a trusty trench—in almost any form. And there’s one cult, perennial bestseller that comes back year after year: Sézane’s Clyde trench coat.

The French brand is, of course, no stranger to a sell-out item, nor is it short of a celebrity fan base. Case in point: Sienna Miller, a long-time Sézane devotee who has been spotted wearing the Clyde trench on repeat. So, I did what any responsible shopping editor would do and tried the much-hyped coat for myself.

First impressions? The Clyde is structured enough to hold its shape beautifully, but not so rigid that it feels overly formal. The slightly oversized silhouette gives it that effortless, slightly cool quality that makes a trench feel particularly modern, while the longline cut instantly elevates even the simplest jeans-and-T-shirt combination. It’s roomy enough to layer a knit underneath once temperatures really start to dip, too, without feeling bulky.

Shopping Editor Marina wearing the Sezane trench coat

What struck me most, though, is just how considered the proportions feel. Trench coats can easily swamp the frame—particularly when you’re petite—but the Clyde manages to feel intentionally oversized rather than simply too big. I opted for a size 10 to ensure I had enough room for layering once the temperatures begin to drop, and it fit my 5"2 frame perfectly. The details are classic rather than trend-led, which is exactly what I’d want from a coat I’m investing in with the intention of wearing for years.

And therein lies the Clyde’s appeal. It’s not trying to reinvent the trench coat; instead, Sézane has taken all the elements that make the style such an enduring wardrobe staple and made them feel just a little cooler. Having finally tried it myself, I can understand why it resurfaces every autumn—and why its fan base keeps growing.

Keep scrolling to shop Sézane's Clyde trench coat below.