1966. Helen Reddy (Tilda Cobham-Hervey) arrives in New York with her three-year-old daughter, a suitcase and $230 in her pocket. Helen had been told she had won a record deal, but the record company promptly dashes her hopes by telling her it had enough female stars and suggests she has fun in New York before returning home to Australia.
Helen decides to stay in New York anyway and pursue a singing career, struggling to make ends meet and provide for her daughter due to not having a work permit. There she befriends legendary rock journalist Lillian Roxon (Danielle Macdonald), who becomes her closest confident, and inspires her to write and sing the iconic song 'I Am Woma' which becomes an anthem for the second wave feminist movement and galvanizes a generation of women to fight for change.
She also meets Jeff Wald (Evan Peters), a talent manager who becomes her agent and husband. Jeff helps her get to the top, but he also suffers from a drug addiction, which gradually turns their relationship into a toxic one. Caught in the treadmill of fame and dependent on Jeff to manage her professional life, Helen has to find the strength to take ownership of her career and keep pursuing her dream.