Harry Balter: Harry Balter is a white boy of about Lauren's age. He is the boyfriend of Joanne Garfield, who is his cousin. When the Garfields move to the company town of Olivar, Joanne wants Harry to go too, but he refuses. When Lauren's neighborhood is overrun by thieves and arsonists, Harry is one of the few survivors, and he and Lauren, along with Zahra, escape together. He does not wholly trust Lauren because he thinks she is too ruthless, and at first he does not take Earthseed seriously. But he become a reliable member of the group.
Taylor Franklin Bankole: Taylor Franklin Bankole is a fifty-seven-year-old African-American doctor. He joins Lauren's group about four weeks after their trek north begins; he is heading toward some land he owns in the hills on the coast near Cape Mendocino, where his sister and her family live. Bankole's wife was murdered five years ago by drug addicts who broke into their home while he was away. He takes to the road after his community in San Diego is destroyed by arsonists, just as Lauren's neighborhood was. Bankole and Lauren are attracted to each other, and in spite of the difference in their ages, they become lovers.
Gloria Natividad Douglas: Gloria Natividad Douglas is the wife of Travis Douglas. They are the first people to join Lauren, Harry and Zahra on the journey north. Natividad, who is Hispanic, used to work as a maid in the same house where Travis was the gardener and handyman. They left because their employer was subjecting Natividad to sexual harassment.
Travis Charles Douglas: Travis Charles Douglas is the husband of Natividad. He is a self-educated black man. His mother worked as a live-in cook and used to sneak books to him from their employer's library. After his mother died he married Natividad and stayed on as gardener and handyman. They fled their employer when he made sexual advances on Natividad. Travis becomes very interested in Earthseed and Lauren regards him as her first convert.
Dominic Douglas: Dominic Douglas is the six-month-old son of Natividad and Travis Douglas.
Amy Dunn : Amy Dunn is a three-year-old-girl in Lauren's neighborhood in Robledo. She sets fire to the family garage, and not long after this she is accidentally shot dead after she wanders outside.
Tracy Dunn: Tracy Dunn is Amy Dunn's mother. She is only sixteen, and was made pregnant by her uncle when she was twelve. He had been raping her for years. Tracy She disappears one day and is never found.
Joanne Garfield: Joanne Garfield is Harry Balter's girlfriend in Lauren's community in Robledo. She is also a friend of Lauren, and Lauren confides in her about the deteriorating security situation and her plans to leave. Joanne reports this to her parents and Lauren does not trust her any more. Joanne moves with her family to the company town of Olivar before the neighborhood is overrun.
Allie Gilchrist: Allie Gilchrist is a young white woman and Jill's sister. They are both from Glendale, in Los Angeles County. Allie and Jill were forced into prostitution by their father. When she had a baby, her father beat him to death when he was only a few months old. Allie and Jill then burned down the house and took to the road. They are buried in the rubble of a house after an earthquake, and Lauren's group rescues them. They then join the group. Allie takes special care of Justin Rohr, virtually adopting the boy as her own.
Jill Gilchrist: Jill Gilchrist is Allie's sister. They are both fleeing from a tyrannical father who enslaved them in prostitution. Neither of them can write, although they can read a little. Jill is killed rescuing Tori Solis when Lauren's group is attacked by a gang of pyro addicts.
Bianca Montoya: Bianca Montoya is a seventeen-year-old girl in Robledo who becomes pregnant by her boyfriend, Jorge Iturbe. They choose to marry and stay in Robledo even though they have no prospects and all they will have to live in after marriage is half-a-garage.
Doe Mora : Doe Mora is the eight-year-old daughter of Grayson Mora.
Grayson Mora : Grayson Mora is a Latino and the father of Doe Mora. He is the last person to join Lauren's group. Lauren does not trust him because he does not mix well with the group, but she accepts the fact that he loves his daughter and does what is best for her. Later it transpires that Mora, like Lauren, is a "sharer."
Richard Moss: Richard Moss is an engineer for a water company. He is the husband of Zahra, who is the youngest of his three wives. He purchased he when she was fifteen. Moss has invented his own patriarchal religion by combining parts of the Old Testament with traditional West African practices. This allows him to have many wives and to keep them under his control. Moss is killed when the Robledo neighborhood is burned to the ground.
Zahra Moss: Zahra Moss is Richard Moss's husband. He purchased her from her homeless mother when she was fifteen. Zahra has a baby daughter, Bibi, who is killed when the Robledo neighborhood is finally overrun. Zahra also witnesses the killing of Lauren's family. With Harry Balter, Zahra is one of the few survivors, and she joins the other two and walks north. Zahra can neither read nor write, and Lauren begins to teach her.
Cory Olamina: Cory Olamina is Lauren's stepmother. She holds a Ph.D. degree and is a teacher in charge of the neighborhood school. She wants to move to Olivar, but her husband will not allow it. After her husband's death, she takes over some of his teaching duties at the college. Her favorite son is Keith. Cory dies when the neighborhood is destroyed.
Keith Olamina: Keith Olamina is twelve years old, the oldest of Lauren's three brothers. He and Lauren do not like each other, and she calls him the most sociopathic person she has ever been close to. Keith does not like doing anything other than hang out with his friends. He dodges work, school and church whenever he can, although this does not stop him being Cory's favorite son. When he is thirteen he runs away from home and lives in abandoned buildings with drug addicts and thieves. He steals money and brings some of it home for his mother. But his dangerous lifestyle does not last for long. He is tortured and killed, probably by the drug dealers he considered his friends.
Gregory Olamina: Gregory Olamina is Lauren's youngest brother. He is killed when the neighborhood is destroyed.
Lauren Olamina : Lauren Olamina is the narrator and heroine of the novel. She is fifteen years old when the story begins. Lauren is African-American, intelligent and well-educated, already having taken some college-level courses. She thinks for herself and has strong leadership qualities. One difficulty she has to cope with is that she suffers from "hyperempathy syndrome." This means that she feels other people's pain and pleasure as if they were her own. She believes this to be a weakness and tries to keep it a secret as much as possible. Lauren acquired the syndrome because her mother was addicted to the prescription drug Paracetco. Her mother died giving birth to Lauren.
Lauren is more aware than anyone else that her Robledo neighborhood will soon be destroyed, and she already has plans in place when the disaster happens. Although in this catastrophe she loses her entire family, she does not allow the terrible experience to break her spirit, and she heads north with Harry and Zahra in search of a better life. She is the undisputed leader of her small group, and it is thanks to her that they survive. Lauren is physically strong and also very resourceful. She figures out what is needed in terms not only of supplies but also mental attitude. Lauren is also a thinker and a visionary who keeps a journal of her thoughts about God. Lauren's God is not the God of her Baptist preacher father, but a new concept altogether, of God as an impersonal force of change that can be shaped by humans. As Lauren leads the way north she develops and refines her thinking. She believes she is founding a new religion, which she calls Earthseed. As she and her group make their way north, Lauren shows that she can be ruthless. She will not hesitate to kill when there is no other choice, but she is also compassionate, sharing with others what she has, and teaching the group how to look after one another. She teaches Zahra, and later Jill and Allie, how to read. She is rewarded when the group finally arrives on some land that gives them a chance of succeeding as the world's first Earthseed community.
Marcus Olamina: Marcus Olamina is Lauren's eleven-year-old brother. He is a trustworthy boy and at age thirteen his beautiful appearance is already beginning to attract girls.
Reverend Olamina: Reverend Olamina is Lauren's father. He is a Ph.D. and he teaches at the local college. He is also a Baptist minister. His own parents were murdered and his first wife died giving birth to Lauren. Reverend Olamina is a strict disciplinarian who beats his children when he thinks it necessary. When he beats Keith severely for running away from home, Keith never forgives him. Reverend Olamina also takes every possible measure to protect his family and the neighborhood from attack, and Lauren respects him. Reverend Olamina disappears one day, and never returns. He is presumed dead.
Wardell Parish: Wardell Parish is a cantankerous old man who lives in Lauren's neighborhood. He is widower twice over with no children. Lauren calls him a "strange, solitary, whiny man."
Justin Ruhr: Justin Ruhr is a three-year-old boy who is taken in by Lauren's group after his mother is killed. He is taken care of by Allie.
Emery Tanaka Solis: Emery Tanaka Solis is a twenty-three-year-old woman of mixed racial origins. Her father was Japanese and her mother was black. After the death of her Mexican husband, Emery found herself in debt slavery to the company they worked for, and when the company took her two sons, she decided to take her daughter Tori and run away. The two of them join Lauren's group near the end of the journey north.
Tori Solis: Tori Solis Tori is the nine-year-old daughter of Emery Solis.
Curtis Talcott: Curtis Talcott is Lauren's boyfriend in Robledo. He wants to marry her and leave Robledo, but she puts him off, saying she must stay with her family until she is eighteen. Although she loves him she feels there is too much of herself that she cannot share with him. After the neighborhood is destroyed, Lauren does not know what happened to Curtis. It is likely that he was killed.