Abdul
Abdul is the main character of the narrative. His family doesn't know how old he is. According to his mother, he could be anywhere from 17 to 27. He has worked hard for his family since he was six. In fact, Abdul is almost single-handedly responsible for lifting them slightly above the economic level of the slum they live in. He is an expert at sorting and trading garbage. Although somewhat morose, Abdul is a deeply ethical young man who wants to live an exemplary life. When he is falsely accused of inciting Fatima to set herself on fire, his mother is able to bail him out. He resumes his life, but his case is not resolved by the end of the narrative.
Zehrunisa
Zehrunisa Husain is the matriarch of the 11-member Husain family. She is determined and resourceful. She bargains with the scavengers, for example, to increase the family fortunes. When several of her family members are arrested and falsely accused of inciting a neighbor to commit suicide, Zehrunisa works hard to have them freed and get them legal representation. She fails to save the family business while Abdul is in jail, but she continues to be the backbone of the family.
Asha
Asha Waghekar is an ambitious middle-aged woman who aspires to be the slumlord of Annawadi, an informal position she eventually wins. She will help people in Annawadi fix their problems for a price. She even scams the government. First, she takes government funds for running a school—a school her daughter ends up running for her. Then she pretends to run 24 kindergartens. Asha also takes money from men for sex as a side job. Asha's ambition extends beyond herself to her children, especially her teenaged daughter, Manju, who Asha hopes will make her way into the middle class.
Manju
Manju Waghekar, a college student, is the somewhat educated daughter of Asha, the neighborhood fixer. Pretty and kind, she is her mother's best hope for raising the family out of the lower classes. Manju has ambitions to become a teacher and takes on her mother's responsibilities to teach the neighborhood children in a home school, for which Asha is getting paid by the government to run. Later Manju gives up her dream of teaching and instead signs on to her mother's even more lucrative scam of pretending to run 24 kindergartens.
Fatima
Fatima is a crazy, spiteful woman who lives on the other side of the wall of the hut where the Husains live. Fatima has likely drowned one of her children, and she regularly sleeps with other men when her husband is out working. She was scorned and rejected by her original family because of her frailty and carries a lot of rage and spite because people treat her as if she is less than human. Jealous of the Husains' happy family life, Fatima sets herself alight and accuses them of the deed in order to destroy their happiness.
Sunil
Sunil Sharma, a teenaged garbage picker, is friends with Abdul and also works with him. Sunil brings his garbage to the older boy, whom he looks up to. Sunil is a bright and perceptive boy who is often hungry. At first he tries to stay away from stealing and avoid bad habits, like huffing Eraz-ex (the Indian version of "Wite Out" used to correct typed documents). He crosses over to stealing during the desperate time after the economic downturn of 2008 and succumbs to using Eraz-ex to take the edge off his physical and emotional pain. He eventually loses hope that his life can get better.