Julia Fox (born February 2, 1990) is an Italian-American actress and director. She is best known for her debut role in the 2019 film Uncut Gems, for which she was nominated for the Breakthrough Actor award at the 2019 Gotham Awards.

Fox was born in Milan, Italy, to an Italian mother and an American father. Fox spent her early years living with her grandfather. At the age of six, she moved with her father to New York and lived in Yorkville, Manhattan. She worked several service jobs, including at a shoe store, an ice cream shop, and a pastry shop. Fox attended City-As-School High School and worked as a dominatrix for six months.

Before her role in Uncut Gems, Fox was a clothing designer and launched a successful women's knitwear line, Franziska Fox, with her friend Briana Andalore. She also worked as a model, posing for Playboy's final nude issue in 2015, as well as an artist and photographer. She self-published two books of photography: Symptomatic of a Relationship Gone Sour: Heartburn/Nausea, published in 2015, and PTSD, published in 2016. In 2017, Fox held an art exhibition titled R.I.P. Julia Fox, which featured silk canvases painted with her own blood.

Fox made her feature film debut in the Safdie brothers' 2019 film Uncut Gems, playing a showroom saleswoman and the lover of the film's protagonist Howard Ratner (played by Adam Sandler), an unstable jewelry dealer and gambling addict. Fox had known the Safdie brothers for nearly ten years after a chance meeting with Josh Safdie at a cafe in SoHo, Manhattan.