London, 1946. Juliet (Lily James), a charismatic and free-spirited writer receives a letter from a member of a mysterious literary club started in Nazi-occupied Guernsey, a part of the United Kingdom. Her curiosity piqued, Juliet decides to visit the island. There she meets the delightfully eccentric members of the Guernsey Literary and Potato Peel Pie Society, including Dawsey, the rugged and intriguing farmer who wrote her the letter. As the secrets from their wartime past unfold, Juliet's growing attachment to the island, the book club and her affection for Dawsey will change the course of her life forever.