Hannah is a German Jewish woman who flees to Paris to work at the German Library of Burned Books following a deep betrayal in Berlin. Guarded but fiercely dedicated, she attempts to counter Nazi propaganda while managing fears for her captive brother, Adam. She draws strength from her Jewish heritage and remains dedicated to the protection of marginalized literature.

Althea is a newly successful American author from Maine who travels to Berlin on a cultural residency. Initially naive and enchanted by her new cosmopolitan life, she views the world through the lens of fairy tales and storytelling. As the political reality of her hosts becomes apparent, she must confront her own willful ignorance and find the courage to stand by her true beliefs.

Vivian is a passionate champion of the Armed Services Editions living in New York in 1944. Recently widowed, she channels her grief into a relentless political battle against proposed legislation that would ban certain books from being sent to soldiers overseas. She uses her resourcefulness to build a high-profile campaign against censorship on the home front.

Deveraux is a confident, high-profile actress and screenwriter participating in the same Berlin exchange program as Althea. Worldly and sophisticated, she acts as a guide to Berlin's vibrant underground culture. She possesses a ruthless pragmatism that allows her to maneuver through high-society circles while harboring her own hidden agendas.

Otto is Hannah’s childhood friend and an open member of Berlin's LGBTQ community. He shares an innate, deeply ingrained trust with Hannah that makes them feel like extensions of one another. As the political climate darkens, his inherent weakness and fascination with violent resistance tactics cause him to grow increasingly unstable.

Senator Taft is a powerful American politician proposing a censorship law that would restrict the literature sent to soldiers abroad. He argues his policies target overt political agendas, entirely disregarding the morale-boosting benefits the books provide. He represents the systemic threat of censorship on the home front.

Hale is Edward's half-brother, born from their father's affairs, and Vivian's first love. After a period of estrangement driven by his own insecurities, he reconnects with Viv in New York to assist with her campaign against Senator Taft. He shares Viv's appreciation for literature and offers a steadying presence as she advances her political ambitions.

Edward is Viv's recently deceased husband who loses his life fighting overseas. His final correspondence to his wife outlines his appreciation for the Armed Services Editions, sparking Viv's crusade. Though their marriage was built on practical support and deep friendship rather than romantic passion, his memory serves as a guiding force.

Adam is Hannah's brother and an active participant in Berlin's dangerous resistance movement. He is passionate, deeply committed to fighting oppression, and increasingly reckless in his methods. His actions draw the attention of the regime, creating a devastating ripple effect for his sister and her circle of friends.

Diedrich is a handsome, charismatic liaison assigned to Althea during her cultural residency. He initially appears as a perfect host, offering her attention and gifts. However, his sophisticated charm serves as a dispassionate facade for his true dedication to the rising Nazi party and its oppressive ideologies.

Charlotte is Edward's mother and Viv's mother-in-law. She lives with Viv in New York and maintains an idealized perception of her son's marriage. She also attempts to stay involved in the life of her stepson, Hale, despite their complicated family history.

Mr. Stern is the head of the Council on Books in Wartime in New York. He manages the distribution of the Armed Services Editions and initially expresses hesitation about Viv's aggressive tactics. However, he is ultimately swayed by her passion and the evidence of the soldiers' letters, agreeing to support her public campaign.

Lucien is the grandson of Jewish shopkeepers in Paris who secretly organizes resistance meetings. He attempts to recruit Hannah to his cause, though she prefers non-violent methods. He serves as a connection to the rising underground resistance in France as the threat of war looms.

Harrison is a prominent editor and friend of Viv in New York. He acts as a sounding board for her political frustrations and brainstorms ways to defeat Senator Taft's legislation. He provides Viv with crucial information, directing her to the American Library of Nazi-Banned Books.

Howard Danes is a political associate of Senator Taft. He approaches Viv on the street, offering a hollow compromise regarding her deceased husband's military honors in exchange for abandoning her anti-censorship crusade.

Joe is Althea's brother who lives in their hometown of Owl's Head, Maine. He provides Viv with transportation and a local perspective on his reclusive sister when Viv arrives attempting to recruit her.

"Georgia" is the nickname Viv gives to a young soldier from the South whom she meets just before his deployment. Struggling with literacy, he worries about reading his mother's letters while at war, prompting Viv to give him a memorable, joyful day in the city.

Edith is Viv's colleague at the Council on Books in Wartime. She works alongside Viv to manage the book selections and helps brainstorm high-profile guests for the anti-censorship event, specifically suggesting the reclusive Althea James.

Joseph Goebbels is an aspiring politician in the rising Nazi party who interacts with Althea during her cultural residency. He serves as a primary architect of the regime's propaganda and the catastrophic public book burnings.

Brigitte is Hannah's abrasive landlady in Paris. Despite her typically gruff exterior, she demonstrates surprising compassion when Hannah receives devastating personal news, stepping in to care for her tenant.

Natalie is a friend of Hannah's in Paris who hosts gatherings and discusses art, survival, and the philosophy of kintsugi. She provides Hannah with crucial information regarding Deveraux's presence in the city.

Patrice is a member of Hannah's social circle in Paris. Managing her own romantic complications, she shares a brief, intimate connection with Hannah as they both seek comfort in a turbulent time.

Helene is a vain, pretentious woman Althea encounters in Berlin. As a passionate supporter of Hitler, she casually discusses the party's goal to "Aryanize" the community, providing Althea with a blunt look at the casual cruelty of the regime's supporters.