In 1952, Irish teenager Philomena (Judi Dench) became pregnant out of wedlock and was sent to a convent. When her baby, Anthony, was a toddler, the nuns took Philomena's child away from her and put him up for adoption in the United States. For the next 50 years, she searched tirelessly for her son. When former BBC correspondent Martin Sixsmith (Steve Coogan) learns of the story, he becomes her ally. They travel together to America to find Anthony and become unexpectedly close in the process.