Sydney Sweeney

Sydney Sweeney looked ethereal in an icy blue dress at the premiere of "Echo Valley." (Mike Marsland/WireImage)

Sydney Sweeney looked ethereal while walking the red carpet at the European premiere of "Echo Valley" in an icy blue Miu Miu dress with a halter neckline, fitted bodice and a keyhole cutout on her chest.

She posted photos from the evening on her Instagram, captioning the posts, "London