Lola Dewaere is the daughter of actor Patrick Dewaere and Élisabeth (known as Elsa) Malvina Chaillet. She is the half-sister of Angèle Herry-Leclerc (born 1974), the daughter of Patrick Dewaere and actress Miou-Miou, whom Julien Clerc adopted in 1992.

After her father's suicide on 16 July 1982 in Paris, her mother faced tax authorities over the debts he left behind and entrusted Lola to her parents, who lived in Saint-Lambert-du-Lattay (Maine-et-Loire). Coluche offered to become Lola's godfather at her christening, but her grandparents refused.

Although she was bright, she was often disobedient and struggled at school. She developed certain complexes, in particular because of her tall stature, her grandparents' high expectations and the frequent mentions of her father. In early adolescence she returned to live with her mother in Paris and continued her schooling at the private Catholic school Saint-Michel-de-Picpus from the seventh grade. A rebel who refused to recognize authority, she was expelled. During this period, anything to do with her father was a forbidden subject. However, her mother sometimes mentioned his suicide in, as Lola describes it, "very harsh" terms, saying that he shot himself in the mouth.

At around 16 she nevertheless discovered several of her father's films, among them *Headbutt*, *The Best Way to Walk*, *Goodbye, Cop* and *Psy*, and she liked them. In 1997, having come of age, she enrolled at the Cours Florent drama school to train as an actress.