Rachel Zegler was born in Hackensack, New Jersey, to Gina and Craig Zegler. Her mother is of Colombian descent, and her father is of Polish descent. This diverse background would later influence her career choices and experiences.

Zegler saw her first Broadway show, "Beauty and the Beast", at the Lunt-Fontanne Theatre. This experience sparked her love for theater and set her on the path to becoming an actress.

Zegler played Shprintze in a play of "Fiddler on the Roof". This role marked the beginning of her acting career, leading her to take voice and acting lessons.

Zegler started her YouTube channel, where she posted videos of herself singing. Her cover of Lady Gaga's song "Shallow" from "A Star Is Born" gained significant attention and positive critical reception.

Director Steven Spielberg posted an open casting call for a new film adaptation of "West Side Story". Zegler, then 16, responded with videos of herself singing "Tonight" and "I Feel Pretty". She was selected from over 30,000 applicants for the role of Maria.

Zegler made her film debut in Steven Spielberg's musical adaptation of "West Side Story", playing the role of Maria. Her performance earned her the Golden Globe Award for Best Actress – Motion Picture Musical or Comedy, making her the first actress of Colombian descent to win in that category and the youngest winner at 20 years old.

Zegler played Anthea in "Shazam Fury of the Gods" and Lucy Gray Baird in "The Hunger Games: The Ballad of Songbirds & Snakes". Her performance in "The Hunger Games" prequel received positive reviews, with David Ehrlich of "IndieWire" praising her "captivating" and nuanced performance.

Zegler made her Broadway debut playing Juliet in a musical adaptation of William Shakespeare's "Romeo & Juliet", directed by Sam Gold with music by Jack Antonoff. This marked a significant milestone in her career, fulfilling a dream she had since she was 4 years old.

Zegler appeared in Kyle Mooney's directorial debut film "Y2K" and voiced the lead character in the animated musical film "Spellbound", directed by Vicky Jenson.

Zegler is set to play the titular character in "Snow White", a live-action adaptation of the 1937 animated Disney film, scheduled to be released in 2025.