Daniel is a young man living above a rare and used bookshop with his widowed father in Barcelona. At ten years old, he selects a copy of The Shadow of the Wind from a hidden labyrinth of books, which sparks a lifelong obsession with its author. He possesses a strong sense of curiosity and loyalty to his friends. His desire to uncover the truth leads him into dangerous encounters with city authorities.

Julián is a forgotten author who published several unsuccessful novels in Paris before the Spanish Civil War. He grew up in Barcelona as the son of a local hat maker and attended San Gabriel's School through the sponsorship of a wealthy patron. Rumors circulate that he died penniless in an alley. His surviving books are extremely rare.

Fumero is a corrupt police inspector who survived the political shifts of the Spanish Civil War by constantly changing his allegiances. As a boy, he attended San Gabriel's School alongside Julián Carax, displaying deeply disturbing behavior and a fascination with weapons. He uses his authority to intimidate and eliminate anyone who crosses his path.

Beatriz is a university student studying literature and the sister of Daniel's best friend. She dresses in expensive clothing and is engaged to marry an army officer named Pablo. She possesses a bold personality and challenges Daniel's assumptions, eventually drawing him into exploring abandoned parts of the city with her.

Fermín is a talkative, highly intelligent former secret service agent who lost his position following the Spanish Civil War. He lives on the streets until the Sempere family offers him employment and shelter. He uses his espionage skills to help Daniel investigate the history of Julián Carax.

Mr. Sempere runs a shop for rare and used books in Barcelona. He is a gentle, compassionate widower who honors the memory of his late wife. He acts as a steadying presence in Daniel's life and extends his generosity to others in need.

Penélope is the daughter of a wealthy Barcelona businessman. She grew up in a luxurious but oppressive household called The Angel of the Mist. She met Julián Carax as a young teenager, sparking an intense romance that faced severe opposition from her strict family.

Jorge is the son of a powerful executive and a student at San Gabriel's School. He forms a close friendship with Julián Carax before tensions over his sister divide them. He struggles under the harsh expectations of his tyrannical father, who frequently belittles him in front of his peers.

Don Ricardo is an unscrupulous, wealthy business executive who rules his household with an iron fist. He purchases a notorious mansion for his family despite its dark history. He sponsors Julián Carax's education but treats his own son with open disdain.

Tomás is a large, physically imposing young man who speaks fluent Latin and enjoys discussing mathematics. His father dismisses his intellect because of a stammer. He is intensely protective of his sister and values his bond with Daniel.

Miquel is the son of an arms manufacturer who attended San Gabriel's School with Julián Carax. He views his family's wealth as blood money and actively tries to spend it on rebuilding community institutions. He provides crucial financial support to Julián during their school years.

Nuria worked as a translator and secretary for the publisher who distributed Julián Carax's novels. She speaks French, Italian, and German, which allowed her to correspond with foreign authors. She hid the last surviving copies of Carax's books in the Cemetery of Forgotten Books to keep them safe.

Isaac is the elderly keeper of the cavernous Cemetery of Forgotten Books. He allows Daniel to take shelter in his office during a storm and provides the first concrete clues about the publishing history of Julián Carax's novels.

Clara is the blind, beautiful niece of a wealthy book collector. She lost her father during the Spanish Civil War and spent time in France, where she first discovered the works of Julián Carax. She captivates the young Daniel, who spends years visiting her apartment to read aloud to her.

Antoni runs a hat shop below his apartment in Barcelona. He is an ignorant, abusive man who treats his wife poorly and views his imaginative son as a disappointment. He eventually experiences a change of heart, attempting to make amends for his past cruelty.

Father Fernando is a priest and teacher who previously attended San Gabriel's School as a scholarship student. He shares his memories of his former classmates with Daniel and Fermín, providing context about the strange dynamics between the boys.

Jacinta is the former governess for the wealthy Aldaya family. She devoted her life to caring for Penélope Aldaya from birth, acting as her closest confidante. She experiences prophetic visions of a dark figure named Zacarías who predicts events in her life.

Don Gustavo is a wealthy, knowledgeable book collector who retains the leisure and opulence of the upper class. He immediately attempts to purchase Daniel's copy of The Shadow of the Wind for a large sum of money and maintains connections throughout the literary world.