In 1966, single-mother Helen Reddy (Tilda Cobham-Hervey) leaves her old life in Australia for New York and stardom, only to find that the industry's male gatekeepers don't take her seriously. Helen finds an encouraging friend in legendary rock journalist Lillian Roxon (Danielle Macdonald), who becomes her closest confidant. When ambitious aspiring talent manager Jeff Wald (Evan Peters) sweeps Helen off her feet, everything changes as he becomes both her husband and manager and relocates the family to California. With a strong push from Helen, Jeff secures her a recording contract and subsequent string of hit singles, including the iconic megahit "I Am Woman." Increased fame leads to added pressures on themselves and their relationship, forcing Helen to find the strength to take control of her own destiny.