Lauren is the founder of the Earthseed spiritual movement and the leader of the Acorn community in rural California. As a Black woman with hyperempathy syndrome, she physically feels the pain and pleasure of anyone near her. She is highly intelligent, pragmatic, and heavily invested in her belief that humanity must leave Earth to establish colonies on other planets. Her intense commitment to Earthseed often requires her to project a cold, detached exterior to mask her internal suffering.

Larkin is the daughter of Lauren and Bankole, serving as the primary assembler and co-narrator of the text. Raised away from the Acorn community in an unhappy, strictly religious adoptive household, she grows up feeling isolated and resentful. She works as a historian and creates virtual reality scenarios, demonstrating a sharp, analytical mind often colored by her bitterness toward her biological mother.

Bankole is a doctor and Lauren's romantic partner, older than her by nearly four decades. He provides essential medical care to the residents of Acorn and neighboring towns. He prioritizes safety and physical security, frequently urging Lauren to move their family to a more established settlement rather than risking their lives in the increasingly violent country.

Marcus is Lauren's brother, miraculously surviving the destruction of their childhood home in Robledo. After enduring severe trauma and exploitation, he adopts a highly conservative worldview and becomes a popular preacher within the Christian America movement. He values strict order, security, and traditional authority structures, putting him at ideological odds with his sister.

Jarret is the leader of a fundamentalist religious sect called Christian America who wins the United States presidency in 2032. He appeals to disenfranchised citizens by promoting an aggressive, idealized return to traditional values. His followers violently persecute non-believers, making him a direct threat to Earthseed and other minority communities.

Madison is a middle-class Black Christian American living in Seattle. He takes in Larkin more out of a sense of duty than genuine affection. He runs a strict, oppressive household and sexually abuses Larkin throughout her youth, driving her to eventually flee the family.

Kayce is Madison's wife and Larkin's adoptive mother. She remains trapped in grief over the death of her biological daughter, Kamaria, who died in a missile attack. She constantly compares Larkin unfavorably to Kamaria, ensuring Larkin never feels truly welcome or loved in the home.

Len is a woman from a wealthy background who was ostracized by her family following a kidnapping. She travels with Lauren toward Alaska, seeking to reunite with relatives. Like Lauren, she has hyperempathy syndrome, making her uniquely receptive to Lauren's teachings about Earthseed and survival.

Dan is a teenage boy who survives a brutal armored truck attack that kills his parents. While recovering at Acorn, he learns about Earthseed but remains intensely focused on finding and rescuing his two older sisters who were abducted during the raid.

Kassia is one of Dan Noyer's younger sisters. She survives a lethal attack on her parents and is brought to Acorn, where the community helps her heal and mourn.

Mercy is a young child in the Noyer family who survives a deadly assault on the road to Alaska. The Acorn community takes her in and provides physical and emotional care.

David is a prisoner at the re-education camp who shares vital information with Lauren about the broader political situation outside the fences. He attempts to lead an organized uprising against their captors, demonstrating his resistance to the brutal conditions.

Joel is a wealthy resident of Portland who, along with his wife, becomes fascinated by the Earthseed philosophy. He provides critical financial and logistical support to Lauren, helping her digitize her writings to reach a broader audience.

Irma is a wealthy patron who shelters and supports Lauren during her travels. She recognizes the value of the Earthseed movement and helps provide the stability Lauren needs to transition from a fleeing refugee to a public religious figure.

Justin is a young boy who was originally raised in the Acorn community before being abducted and forced into a Christian America adoption. After suffering abuse, he runs away and attempts to find his way back to his original home.

Nia is a former teacher who takes Lauren and Len into her home. As they spend time together, she becomes a trusted confidante to Lauren, ultimately agreeing to help teach the fundamentals of Earthseed in her local area.