Jessica Knoll grew up in the suburbs of Philadelphia, and attended the Shipley School in Bryn Mawr, Pennsylvania. Knoll attended college at Hobart and William Smith Colleges, where she majored in English. After graduating, she moved to New York City and began her career in the magazine industry. She worked at Parenting magazine, and then at Popular Science and Self. Knoll eventually began working at Cosmopolitan magazine, where she built a successful career and eventually became a senior editor.
Knoll wrote her first novel, Luckiest Girl Alive, while working at Cosmopolitan. It was published in 2015, and became a bestseller. While promoting the novel, Knoll was repeatedly asked where she drew her inspiration, and she did not initially reveal that she was a survivor of sexual violence. Knoll hid this experience for years, and it was not until she described the events to a therapist when she was in her 20s that she understood that she was not to blame for what happened to her. Knoll has stated that many of the experiences depicted in her novel reflect the aftermath of her own assault: like Ani, she was bullied by other students after the assault, and was made to feel responsible. In March 2016, Knoll published an essay publicly revealing that she had lived through an experience very similar to what Ani undergoes in the novel, and that many of the novel's details were drawn from her own experiences. Knoll was moved to tell her own history after realizing that many of her readers had also experienced sexual violence.
Knoll published her second novel, The Favorite Sister, in 2019. She also wrote the screenplay and worked as the producer for the film adaptation of Luckiest Girl Alive, which premiered on Netflix in 2022.