Antonio Juan Márez y Luna - Antonio is 7 and very serious, thoughtful, and prone to moral questioning, and his experiences force him to confront difficult issues that blur the lines between right and wrong. He turns to both pagan and Christian ideologies for guidance, but he doubts both traditions. With Ultima’s help, Antonio makes the transition from childhood to adolescence and begins to make his own choices and to accept responsibility for their consequences.
Gabriel and Maria (Tony's Parents)-hold conflicting views about Tony's destiny. Their battle over which way of life Tony should follow makes it difficult for him to accept either of their cultural traditions. Gabriel represents the roaming life of a vaquero; Maria represents the settled life of farmers and wants Tony to become a priest.
Ultima - An elderly curandera, known in the Márez household as "La Grande" is the embodiment of the wisdom of her ancestors and carries within her the powers to heal, to confront evil, to use the power of nature and to understand the relationship between the seen and unseen. Her role in the community is as mediator. "She preserves the indispensable contact with the world of nature and the supernatural forces inhabiting this universe (255)." She is the spiritual guide for Antonio as he journeys through childhood. Ultima knows the ways of the Catholic Church and also the ways of the indigenous spiritual practices over which she is master. Ultima understands the philosophy and the morality of the ancient peoples of New Mexico and teaches Tony through example, experience and critical reflection, the universal principles that explain and sustain life. Although she is generally respected in the community, people sometimes misunderstand her power. At times she is referred to as a bruja, or witch, but no one—not even Antonio—knows whether or not she is truly a witch. Finally Antonio puts pieces of the puzzle together and the revelation of who she is comes to him. She holds Antonio's destiny in her hands, and at the end of the story sacrifices her own life so that Antonio might live.
Tenorio Trementina and his three daughters - Tenorio is a malicious saloon-keeper and barber in El Puerto. His three daughters perform a black mass and place a curse on Antonio's uncle Lucas Luna. Tenorio detests Ultima because she lifts the curse on Lucas and soon after she does so, one of Tenorio’s daughters dies. Hot-tempered and vengeful, Tenorio spends the rest of the novel plotting Ultima’s death, which he finally achieves by killing her owl familiar, her spiritual guardian. Afterwards, he tries to kill Antonio but is shot by Uncle Pedro.
Ultima's Owl -Embodies Ultima's soul, the power of her mysticism, and her life force. The song the owl sings softly outside Antonio’s window at night indicates Ultima’s presence and magical protection in Antonio’s life. Ultima's owl scratches Tenorio's eye out as he stands in Gabriel's doorway and demands the right to take Ultima away from Gabriel's house. By the end of the novel Tenorio has figured out the connection between Ultima and her owl. By killing Ultima's owl, Tenorio destroys Ultima’s soul and life force, which leads quickly to her death. Antonio takes on the responsibility of burying the owl and realizes that he is really burying Ultima.
Lupito - A war veteran who has post-traumatic stress disorder. After Lupito murders the local sheriff in one of his deranged moments, he is killed by the sheriff and his posse as young Antonio looks on from his hiding place on the banks of the river. Lupito’s violent death provides the catalyst for Antonio’s serious moral and religious questioning.
"Lucas Luna" - Antonio's uncle, who gets cursed by the Trementina sisters when he tries to stop them from practicing black magic. As a result, he gets so sick that Ultima is summoned to cure him. She concocts a potient of herbs, water, and kerosene as a purgative and uses Antonio's innocence as a mediator to effect the cure.
Narciso - Although known as the town drunk, Narciso cuts a large, strong figure of a man. Narciso and Gabriel are good friends because they share a deep and passionate love for the llano. Narciso has a deep abiding loyalty and love for Ultima because of her extraordinary efforts to save his young wife who had succumbed to an epidemic that struck the town. Narciso demonstrates a strong appreciation for the richness of the earth —his garden is a lush masterpiece full of sweet vegetables and fruits. Tenorio kills him as he is on his way to warn Ultima that Tenorio is after her. As he lies dying in Antonio's arms, he asks Antonio to give him a blessing.
Téllez - One of Gabriel’s friends. He challenges Tenorio when Tenorio speaks badly of Ultima. Not long afterward, a curse is laid on his home. Ultima agrees to lift the curse, explaining that Téllez’s grandfather once hanged three Comanche Indians for raiding his flocks. Ultima performs a Comanche funeral ceremony on Téllez’s land, and ghosts cease to haunt his home.
Antonio’s friends: Abel, Bones, Ernie, Horse, Lloyd, Red, and the Vitamin Kid - An exuberant group of boys who frequently curse and fight. Horse loves to wrestle, but everyone fears Bones more because he is reckless and perhaps even crazy. Ernie is a braggart who frequently teases Antonio. The Vitamin Kid is the fastest runner in Guadalupe. Red is a Protestant, so he is often teased by the other boys. Lloyd enjoys reminding everyone that they can be sued for even the most minor offenses. Abel, the smallest boy in the group, frequently urinates in inappropriate places.
Samuel - One of Antonio’s friends. He is also the Vitamin Kid’s brother. Unlike most of Antonio’s friends, Samuel is gentle and quiet. He tells Antonio about the golden carp. It is here that Antonio starts questioning his faith.
Florence- One of Antonio's friends who does not believe in God, but goes to catechism to be with his friends. Florence shows Antonio that the Catholic Church is not perfect. He dies in a very bad drowning accident.
Jasón Chávez - One of Antonio’s friends. He disobeys his father when he continues to visit an Indian who lives near the town. He is described by Antonio as being moody.
Jasón Chávez’s Indian - A friend of Jasón’s who is disliked by Jasón’s father. Cico tells Antonio that the story of the golden carp originally comes from the Indian.
Andrew, Eugene, and León Márez - Antonio’s brothers. For most of Antonio’s childhood, his brothers are fighting in World War II. When they return home, they suffer post-traumatic stress as a result of the war. Restless and depressed, they all eventually leave home to pursue independent lives, crushing Gabriel’s dream of moving his family to California.
Deborah and Theresa Márez - Antonio’s older sisters. Most of the time, they play with dolls and speak English, a language Antonio does not begin to learn until he attends school.
Antonio’s uncles: Juan, Lucas, Mateo, and Pedro Luna - María’s brothers are farmers. They struggle with Gabriel to lay a claim to Antonio’s future. They want him to become a farmer or a priest, but Gabriel wants Antonio to be a vaquero in the Márez tradition. Antonio’s uncles are quiet and gentle, and they plant their crops by the cycle of the moon.
Father Byrnes - A stern Catholic priest with hypocritical and unfair policies. He teaches catechism to Antonio and his friends. He punishes Florence for the smallest offenses because Florence challenges the Catholic orthodoxy, but he fails to notice, and perhaps even ignores, the misbehavior of the other boys. Rather than teach the children to understand God, he teaches them to fear God.
Chávez - Chávez is the father of Antonio’s friend Jasón. Distraught and vengeful, he leads a mob to find Lupito after Lupito kills Chávez’s brother, the local sheriff. He forbids Jasón to visit an Indian who lives near the town, but Jasón disobeys him.
Prudencio Luna - The father of María and her brothers. He is a quiet man who prefers not to become involved in other peoples’ conflicts. When Tenorio declares an all out war against Ultima, he does not want his sons to get involved, even though Ultima saved Lucas’s life.
Miss Maestas - Antonio’s first-grade teacher. Although Antonio does not speak English well, Miss Maestas recognizes his bright spark of intelligence. Under her tutelage, Antonio unlocks the secrets of words. She promotes him to the third grade at the end of the year.
Miss Violet - Antonio's third grade teacher. He, with Abel, Bones, Ernie, Horse, Lloyd, Red, and the Vitamin Kid, set up a play about the First Christmas on a dark and snowy night, which turns into a hilarious disaster because of the ever crazy Bones.
Rosie - The woman who runs the local brothel. Antonio has a deep fear of the brothel because it represents sin. He is devastated when he finds out that his brother Andrew frequently goes to it.
The flying man - This man was Ultima’s teacher and was also known as el hombre volador. He gave her the owl that became her spirit familiar, her guardian, and her soul. He told her to do good works with her powers, but to avoid interfering with a person’s destiny. The invocation of his name inspires awe and respect among the people who have heard about his legendary powers and incites fear in Tenorio Trementina.