In the early 1950s, a young Irish woman named Eilis Lacey leaves her small hometown for a brighter future in Brooklyn, New York. Initially overwhelmed by homesickness and culture shock, Eilis receives support from her boarding house landlady and an Irish priest who arranged her job at a fancy department store. As she gradually starts to acclimate to her new surroundings, Eilis enrolls in night classes to further her education and gain confidence in her new life. Her loneliness begins to fade when she meets Tony, a charming Italian-American guy who quickly wins her heart.

As Eilis and Tony's romance blossoms, she finds herself increasingly torn between her new life in America and her roots back in Ireland. A family tragedy forces Eilis to return home temporarily, where she reconnects with familiar faces and is confronted with new opportunities that make her question where she truly belongs. Back in Ireland, Eilis must decide whether to stay with the comforts of her past or embrace the new possibilities awaiting her across the Atlantic. This emotional journey challenges her to make the toughest decision of her life, reflecting on love, identity, and the place she calls home.