Née Alicia Christian Foster, Jodie was born November 19, 1962, in Los Angeles, California. Her father, Lucius, left the family before her birth, leaving Alicia and her three siblings to be raised by their Hollywood publicist mother, Evelyn Foster. Given her occupation, Evelyn had little problem finding acting work for those of her children that expressed interest in taking it on, and Alicia made her first on-screen appearance at the age of three, in a Coppertone sunscreen commercial. Further commercial work followed, as did small roles on television series such as Mayberry R.F.D. and The Partridge Family, and Foster made her debut film appearance in 1972, in Disney's Napoleon and Samantha.

Foster's interest in acting did not wane as she entered her teenage years, and she continued her film work, albeit for the most part restricted to quirky roles in children's movies. Foster enjoyed an advantage over other child actors in that her performances were not restricted to a single language: a student at Los Angeles' Lycée Francais, Jodie's French was sufficiently fluent by age 14 for her to win a role in 1977's Moi, Fleur Bleue, as well as a number of other French films. Yet Foster's childhood success should not be solely attributed to her linguistic abilities. Even before her appearance in Moi, Fleur Bleue, Foster had demonstrated an acting talent impressive enough to earn a casting call to 1976's Taxi Driver. The film proved to be a contemporary classic, and Foster's role in it, as a teenage prostitute, won her critical acclaim as well as an Oscar nomination for Best Supporting Actress. By age 14, Foster had made the big break that most seasoned actors envy. Throughout the remainder of her high school years, Foster persisted in expanding her professional experience with film and television appearances. While tending to her burgeoning career, Foster continued to attend courses at the Lycée Francais, and in 1980 accomplished the feat of not merely graduating on schedule, but as class valedictorian. Her academic accolades were acknowledged, and Foster was accepted at Yale University, where she began attending lectures in English Literature that fall.