Sydney Sweeney turned 28 years old this month, and this past weekend, she celebrated the milestone with a star-studded bash that left a lot to unpack. A chainmail micro purse, diamond jewelry, silver eyeshadow, and her voluminous blonde Hollywood waves capped off the party fit. TheImageDirect Sydney Sweeney. Sweeney evidently chose stars as her outer space theme, but her party guests interpreted the dress code very differently. Sweeney shared a carousel of photos from her party on Instagram, captioning the post: “Welcome to planet syd 👽🛸🚀.”