Jessica Michelle Chastain was born in Sacramento, California, and was raised in a middle-class household in a Northern California suburb. Her mother, Jerri Chastain, is a vegan chef whose family is originally from Kansas, and her stepfather is a fireman. She discovered dance at the age of nine and was in a dance troupe by age thirteen. She began performing in Shakespearean productions all over the Bay area.

An actor in a production of "Romeo & Juliet" encouraged her to audition for Juilliard as a drama major. She became a member of "Crew 32" with the help of a scholarship from one of the school's famous alumni, Robin Williams.

In her last year at Juilliard, she was offered a holding deal with TV writer/producer John Wells and she eventually worked in three of his TV shows. Jessica continues to do theatre, having played in "The Cherry Orchard", "Rodney's Wife", "Salome" and "Othello". She spends her time between New York and Los Angeles, working in theater, film and TV.

In 2011, she had a prolific year in film. She was nominated for and won a number of awards, including a 2012 Oscar nomination for Best Performance by an Actress in a Supporting Role for The Help (2011).