Sienna Miller hasn't lost any of her trendsetter status. The dreamy coat she's been spotted in multiple times - the most recent being a few days ago - has quickly amassed a celebrity fan club. The latest to join? Gigi Hadid, who wore hers with 90s tortoiseshell sunglasses, an oversized blazer, jeans and everyone's favourite Dr. Martens.
Miller wore the coat with lace up-style hiking boots from Gucci - and what looks like white jeans, a sumptuous yet pleasingly lo-fi outfit for a casual dinner.
But back to the coat, if you need more convincing that it's 'a thing', look to Katie Holmes, who wore hers with trainers from New Balance, and Alexa Chung.
While a first glance led me to believe that said coat might be accompanied with a pretty hefty price tag, on closer inspection (and also thanks to a handy email from the brand) I realised it's actually from Mango.
Part of the brand's Premium range, the double-breasted wool coat is £179.99 and still in stock in a size medium at John Lewis & Partners – ideal, really, seeing as the weather is cold and crisp.
BUY: Alexa Chung's Mango Coat
Mango, Double Breasted Wool Coat, £179.99
And if you don't manage to add one to basket, Mango is also having a sale of some of its dreamiest outerwear. Keep scrolling to see our favourite winter coats that you can wear now - and next year.