Sadie Sink was named a Chanel ambassador in 2023, having a longstanding relationship with the luxury fashion house since they dressed her for her first premiere in 2017. This pivotal moment sparked her interest in the art of fashion, leading to her attendance at various Chanel events and features in their campaigns.

Sadie Sink opened the Undercover Fall/Winter 2018 show during Paris Fashion Week, making her runway debut in a red sweatsuit with a crystal-trim beanie. She was followed by models showcasing unique designs, including slim ties and curled-hem anoraks.