Juliet is a successful London-based author who previously wrote lighthearted columns under the pseudonym Izzy Bickerstaff. Seeking a new direction for her writing after the war, she accidentally discovers a Guernsey literary society through a random piece of mail. She lives independently and values books over superficial social expectations. Her curiosity about the islanders' wartime experiences drives her to correspond with them and eventually visit Guernsey.

Dawsey is a quiet, reserved pig farmer living on the island of Guernsey. He initiates contact with Juliet after acquiring her old copy of a Charles Lamb book. He possesses a gentle demeanor and a watchful nature. As one of the founding members of the local literary society, he relies on books for comfort and connection in the aftermath of the German Occupation.

Elizabeth is a fiery, courageous Guernsey resident who serves as the heart of the literary society. She is absent from the island during Juliet's correspondence, having been arrested and sent to a concentration camp for hiding a forced laborer. The other members revere her for her fierce loyalty and willingness to stand up to authority. She leaves behind a young daughter whom the community raises together.

Sidney is the co-owner of the Stephens & Stark publishing house in London. He serves as Juliet's editor, offering professional advice and keeping her grounded during chaotic situations. He is practical, well-connected, and deeply invested in Juliet's success and personal well-being.

Kit is the young daughter of Elizabeth McKenna and a German soldier. With her mother deported and her father deceased, she lives on Guernsey under the shared guardianship of the literary society members. She carries a small box of mementos to remember her parents. She possesses her mother's fierce spirit and intuitive judgment of others.

Mark is a wealthy, successful American publishing tycoon looking to expand his influence. He courts Juliet aggressively, using his vast resources to track her movements and shower her with attention. He is charismatic and used to getting what he wants, though he shows little interest in Juliet's intellectual pursuits or her friends.

Amelia is a wise, maternal figure on Guernsey who hosted the clandestine roast pig dinner that sparked the society's formation. She acts as a stabilizing force for her neighbors and helps organize the care of young Kit. She carries personal grief from the war but maintains a generous spirit.

Isola is an eccentric Guernsey local who brews homemade elixirs and sells them at the market. She wears vibrant, mismatched clothing and approaches life with uninhibited curiosity. She enthusiastically embraces the society meetings and develops a fast friendship with Juliet, eventually taking up unusual hobbies like phrenology.

Eben is an elderly, stoic farmer on Guernsey who lost much of his family during the war. He relies on classical literature to process his experiences and provide him with emotional strength. He takes pride in his woodworking skills and cares deeply for his surviving grandson.

John is a former valet who impersonated his employer, Lord Tobias Penn-Piers, during the German occupation to protect his own Jewish heritage. Following his eventual discovery and imprisonment in a labor camp, he returns to Guernsey with a heavy burden of trauma. He finds unexpected comfort in the stoic philosophy of Seneca.

Will is a practical Guernsey resident and founding member of the society. When food was heavily rationed during the occupation, he invented a crude pie made entirely of potato peelings to provide refreshments for the group. He discovers a passion for the philosophical writings of Thomas Carlyle.

Remy is a fragile French woman recovering in a post-war hospice after surviving the Ravensbrück concentration camp. She possesses vital information about Elizabeth McKenna's activities during her imprisonment. She struggles with severe physical illness and psychological trauma, carrying intense fears related to her captivity.

Sophie is Sidney's sister and Juliet's closest confidante since their days at boarding school. She lives in Scotland and acts as a sounding board for Juliet's personal anxieties and romantic dilemmas, offering grounded advice from afar.

Adelaide is a rigid, judgmental Guernsey resident who views the world in stark absolutes. She considers anyone who associated with the German soldiers to be a traitor, regardless of their circumstances. She actively attempts to sabotage Juliet's research and malign Elizabeth McKenna's reputation.

Christian is a deceased German medical officer who was stationed on Guernsey during the occupation. Unlike the stereotypically cruel occupying forces, he demonstrates kindness to the locals and shares intellectual interests with islanders. His relationship with Elizabeth causes lasting controversy in the community.

Eli is Eben Ramsey's young grandson. He was evacuated to mainland Britain just before the German occupation of Guernsey, separating him from his family for five years. Upon returning to the island, he copes with the loss of his parents by learning to carve wood.

Peter is a Guernsey islander who uses a wheelchair. During the occupation, he discovers a starving forced laborer in his garden and makes the dangerous decision to hide him. His compassionate act draws Elizabeth into a smuggling effort that leads to severe consequences.

Susan is an associate working at the Stephens & Stark publishing house. She travels with Juliet during the book tour and acts as a protective buffer against aggressive reporters and unwanted public attention.

Billee Bee is Sidney Stark's secretary at the publishing house. She presents herself as helpful but harbors selfish motives, eventually attempting to steal valuable documents to aid a vindictive reporter.

Eddie is a Guernsey local who collaborates with the occupying German forces for personal gain. He trades information about his neighbors for favors and minor rewards, creating lasting bitterness within the community.

Clovis is a Guernsey local who joins the literary society primarily to learn about poetry. He uses his newfound knowledge of William Wordsworth to successfully win the affections of a local widow during the occupation.