Kelly Wearstler (/ˈwɜːrslər/) is an American designer. She attended the Massachusetts College of Art in Boston, where she took architecture classes, and obtained her bachelor's degree in interior and graphic design. Wearstler moved to Los Angeles in her mid-twenties, hoping to work in the film industry as a set decorator.

In 1992, she was a production assistant on the movie HouseSitter, and the following year she served as an uncredited assistant art director on So I Married an Axe Murderer. After working small roles on several sets, she decided not to pursue a film career, though the experience did lead to an interior design commission from a film producer. While working as a hostess at a Beverly Hills restaurant in 1994, she was scouted by a Playboy photographer and was featured as September Playmate of the Month under the name Kelly Gallagher. She used the money from the photoshoot to pay off student loans and help start her interior design business.

She founded her own design firm Kelly Wearstler Interior Design (or KWID) in the mid-1990s, serving mainly the hotel industry, and now designs across high-end residential, commercial, retail, and hospitality spaces. Her designs for the Viceroy hotel chain in the early 2000s have been noted for their influence on the design industry.

She has designed properties for clients such as Gwen Stefani, Cameron Diaz and Stacey Snider, and served as a judge on all episodes of Bravo's Top Design reality contest in 2007 and 2008.

Wearstler has released five books, and her first, Modern Glamour, and more!, was named a best seller by the Los Angeles Times in 2006. Other publications include Domicilium Decoratus and Evocative Style in 2019. Her eponymous luxury lifestyle brand incorporates her own designs as well as pieces she finds at auction houses, and she sells her own furniture, lighting, home accessories, and objets d'art collections. She is the design partner for the Proper Hotel Group.

Kelly is the first interior designer to be part of the MasterClass Series and the first outside designer to partner with Farrow & Ball. She has won numerous awards including AD 100 Hall of Fame, Time Magazine's the Design 100, Elle Decor A-List Designers and Vogue Best Dressed.