Louis is a melancholic vampire who was turned by Lestat in New Orleans in 1791. Prior to his transformation, he was a 25-year-old plantation owner plunged into depression and apathy following the tragic death of his brother. Throughout his eternal existence, Louis suffers from deep guilt over his predatory nature and retains a profound reverence for human life. He spends his decades searching for philosophical answers to questions about morality, God, and the nature of evil.

Lestat is a brash, arrogant, and highly capable vampire who acts as Louis's maker. He views human life with contempt and embraces his predatory nature with thrilling satisfaction. Unlike Louis, Lestat refuses to ponder existential questions, preferring to indulge his immediate appetites, wear lavish clothing, and treat killing as an art form. He uses his power to manipulate those around him, often acting out of spite or a desire for control.

Claudia is a five-year-old girl who is transformed into a vampire by Lestat as a calculated move to keep Louis from leaving. Over the decades, her mind matures into that of a brilliant, ruthless adult, but she remains physically trapped in a child's body. She possesses a chilling lack of sentimentality about human life and kills with precision. As she ages, her physical limitations cause her immense frustration and bitterness toward her creators.

Armand claims to be the oldest living vampire in existence. He presides over a coven in Paris that operates the Theatre des Vampires, a venue where vampires kill humans on stage for the entertainment of oblivious mortal audiences. He possesses the unique ability to influence the minds of other vampires. Weary of his endless life, he views Louis as a connection to the modern age that might cure his chronic apathy.

The boy is an unnamed young reporter conducting the interview that frames the entire novel. He listens intently as Louis describes the horrors, philosophical dread, and physical realities of his existence. Despite hearing firsthand accounts of the suffering caused by immortality, the interviewer remains utterly fascinated and romanticizes the vampire lifestyle.

Babette is a young mortal woman living on a plantation near Louis's property in Louisiana. After her brother's death, she assumes control of the plantation, a scandalous move for a woman at the time. She is strong-willed and initially accepts Louis's guidance, but her intense religious convictions eventually cause her to view him as a demonic entity.

Madeleine is a Parisian doll maker who is consumed by grief following the mortal death of her own child. She pours her maternal longing into creating lifelike porcelain dolls. She becomes obsessively attached to Claudia, viewing the static, immortal child as a replacement for the daughter she lost. She intentionally seeks out the vampire transformation to avoid losing another child.

Santiago is a prominent and highly suspicious member of Armand's coven at the Theatre des Vampires. He distrusts Louis and Claudia immediately, viewing Louis's lingering empathy for mortals as a dangerous weakness. He is deeply committed to the old laws of the vampires and actively seeks to uncover the secrets Louis is hiding.

Morgan is an English painter traveling through Eastern Europe. He becomes trapped in a nightmare when the local villagers rely on brutal superstitions to deal with suspected vampires. His terrifying ordeal provides Louis with a stark look at how mortals in the old world handle the supernatural.

Lestat's father is an ailing, blind mortal man who lives with his vampire son. He represents Lestat's last tangible connection to human society. As his death approaches, he begs his son for forgiveness for his past failings as a parent, but Lestat remains cold and unforgiving.

Louis's brother was a devout young man who experienced intense religious visions of the Virgin Mary and various saints. His fervor led him to ask Louis to sell their property to fund missionary work. His subsequent death from a tragic fall serves as the catalyst for Louis's deep depression and eventual encounter with Lestat.

The musician is a mortal artist who composes music for Lestat. He is drawn into the vampire's extravagant lifestyle through expensive gifts and lavish attention, eventually becoming entangled in the dangerous dynamics between Lestat, Louis, and Claudia.

Emily is Morgan's wife, an English traveler who falls victim to mysterious circumstances while visiting a village in rural Europe. Her corpse becomes the target of the local villagers' intense vampire superstitions.