For its unmatched ability to add dimension to nearly any look, the biker jacket tops our list as one to have for Fall. Clearly, we're not alone — this crew of street-styled and red carpet celebs proves that a slick leather jacket has a place just about anywhere. Whether it's furthering the cool factor on a casual look, like Beyoncé's, or lending a little contrast to a girlier look, à la Blake Lively, this layer is a cool-weather essential. You could very well live in it all season long — and we just might. Click through to see how Emma Watson, Poppy Delevigne, Rachel Bilson, and more style up their versions, and then shop for your own.