In 2002, Julie Powell (Adams) is a young writer with an unpleasant job at the Lower Manhattan Development Corporation's call center, where she answers telephone calls from victims of the September 11 attacks and members of the general public complaining about the LMDC's controversial plans for rebuilding the World Trade Center. To do something she enjoys, she decides to cook every recipe in Mastering the Art of French Cooking (1961) by Julia Child (Streep) in one year; Powell decides to write a blog to motivate herself and document her progress.
Woven into the story of Powell's time in Queens in the early 2000s is the story of Child's time in Paris throughout the 1950s, where she attends Le Cordon Bleu to learn French cooking and begins collaborating on a book about French cooking for American housewives. The plot highlights similarities in the women's challenges. Both women receive much support from their husbands, except when Powell's husband becomes fed up with her excessive devotion to her hobby and leaves her for a short time.
Eventually, Powell's blog is featured in a story published in The New York Times, after which her project begins to receive the attention of journalists, literary agents, publishers, and a dismissive response from Child herself. Although Child's book is rejected by Houghton Mifflin, it is accepted and published by Alfred A. Knopf. The last scene shows Powell and her husband visiting Child's kitchen at the Smithsonian Institution and Child in the same kitchen receiving a first print of her cookbook and celebrating the event with her husband.