Fox is of Irish, French and Native American ancestry and was born in Oak Ridge, Tennessee to Darlene Tonachio and Franklin Foxx, who dropped an “x” from his surname. She has one older sister. Fox’s parents divorced when she was young and she and her sister were raised by her mother and her stepfather. She said that the two were “very strict” and that she wasn’t allowed to have a boyfriend. She lived with her mother until she made enough money to support herself. Fox has also spoken of how poor she was when she was growing up and how she had to make her own toys.
Fox began her training in drama and dance at age five, in Kingston, Tennessee. She attended a dance class at the community center there and was involved in Kingston Elementary School’s chorus and the Kingston Clippers swim team. When Fox was 13 years old, she began modeling. At 10 years of age, after moving to St. Petersburg, Florida, Fox continued her training. Fox attended Morningside Academy, a private Christian school, for her middle school years and finished her high school education at St. Lucie West Centennial High School, though at 17 she was tested out of school via correspondence.