Baní, Dominican Republic: This town was home of La Inca, and Beli, before she moved to the nearby capital Santo Domingo. When Oscar and Lola visit the Dominican Republic for the first time, they visit Baní. When they visit later, they visit Santo Domingo.
Oscar de Leon ("Oscar Wao")- an overweight, nerdy Dominican who can't get a girl and is continually depressed due to being such an outcast. He turns his attentions to writing, writing and reading as much as possible. He finally falls in love with Ybon, but her boyfriend and his cronies beat Oscar to death.
Lola de Leon- raped by neighbor as a little girl, and because of the harsh treatment she received from males her entire life, she is headstrong and willing to stand up for herself. She is very protective of Oscar, and she ends up having a child, Isis, in the end of the story. Lola does not get along with her mother, Beli, at all.
Hypatia Belicia Cabral de Leon ("Beli")- third and final daughter of Abelard and Socorro Cabral and mother to Oscar and Lola. Beli was neglected and abused as a child after the death of her mother and incarceration of her father. She eventually makes it back to her family in the Dominican Republic but later moves to New York after a traumatic beating by some of Truijillo's henchmen.
Yunior- narrator of the story, now a writer and teacher. Playboy in his college years where he roomed with Oscar as a way to score points with Lola, the one girl he seems to have any real feelings for before Oscar's death. He eventually settles down and marries.
Dionisio "The Gangster" or "Max Gomez"- Beli's first real, reciprocated love. “The Gangster” is high on Trujillo's list of associates yet he impregnates Beli despite the fact that he is married to Trujillo's sister. She proves every bit as cruel as Trujillo, and has Beli beaten until she looses the baby.
Socorro Cabral- Abelard's wife, the ledgendary nurse at his side. Socorro seems to possess the dream premonition powers as other women in the Cabral family; she dreams about a man without a face that seems to be a death omen.
Jaqueline Cabral- Eldest daughter of Abelard, Jaqueline is very beautiful and Abelard worries constantly that Trujillo will want to rape her if he ever sees her.
Astrid Cabral- Youngest daughter of Abelard, Astrid is more homely but very intelligent and kind.
Lydia- Abelard's main mistress, Lydia continuously begs Abelard to come live with her and start their own family. She provides advice for Abelard in his moments of crisis.
Ybon- Oscar's first reciprocated love, and also his first and last sexual partner. Ybon is a prostitute who moved to the Dominican Republic and also has a scary ex-boyfriend who also threatens to hurt Oscar.
Maritza Chacon- One of Oscar's first girlfriends. Maritza is beautiful and well-liked, and Oscar ultimately chooses her over Olga after a week of dating both of them. Maritza repays him by flirting with another guy at the bus stop.
Olga Polanco- Oscar's other first girlfriend. Olga is described as more homely and quiet than Maritza, although the other children make fun of her because she smells bad and is Puerto Rican. Oscar seems to like her better but breaks up with her for Maritza because she is more popular. Her descriptions later as fat and miserable seem to parallel Oscar's guilt and obsession over women—as these grow, so does Olga.
Al & Miggs- Oscar's two best friends in high school. Both are very nerdy, yet they consider Oscar to be even less well-liked than themselves because he is fat.
Jose & Juan Then- Owners of the restaurant Beli worked in after dropping out of school.
Jack Pujols- Beli's first boyfriend, Jack attended same prep school as Beli and when they were caught together Beli was expelled.
Max Sanchez- Lola's first real boyfriend and love.
“The only way out is in. And that’s what I guess these stories are all about.” –Lola de León