Lilith is a 26-year-old Black woman and survivor of a devastating nuclear war on Earth. Before the war, she lived in Los Angeles, studied anthropology, and lost her husband and son in a tragic accident. The extraterrestrial Oankali select her to Awaken and train the first group of human survivors for a return to Earth due to her intelligence, adaptability, and capacity for tolerance. She experiences profound isolation as she tries to bridge the gap between her human charges and her alien captors.

Nikanj is a young ooloi, the third gender of the Oankali species, tasked with teaching Lilith about its people while learning about humanity from her. It possesses the unique Oankali ability to manipulate genetics and neural pathways, which it uses to alter Lilith's memory and physical strength. As Nikanj undergoes its final metamorphosis into adulthood, it develops sensory arms and relies heavily on Lilith for care during its vulnerable transition.

Joseph is a calm, analytical, and intelligent human who quickly becomes one of Lilith's strongest allies. He approaches the bizarre reality of the Oankali ship by gathering facts and maintaining observation rather than immediately acting on fear. He develops a romantic relationship with Lilith, though their dynamic becomes complicated when Nikanj integrates itself into their physical connection.

Jdahya is a male Oankali who serves as Lilith's first point of contact with the alien species. He acts as her initial teacher, helping her overcome her terror of his appearance and explaining the history of the Oankali's rescue of humanity. He previously lived with a human doctor and possesses a deep, patient understanding of human fear and xenophobia.

Kahguyaht is an adult ooloi and the head of Jdahya's household. It initially treats Lilith with condescension, doubting that a human woman is the appropriate choice to lead the first group of Awakened survivors. As it observes Lilith's dedication to caring for Nikanj, Kahguyaht's opinion shifts, and it begins to treat her with increased respect and trust.

Tate is an intelligent, strong-willed woman whom Lilith selects first because of her calming influence and flexibility. She provides immediate assistance to Lilith in dressing and soothing the newly Awakened humans. While she initially struggles to believe they are truly on an alien ship, she maintains a practical approach to survival.

Curt is a former New York City police officer with a powerful physical presence and a strong need to take control of his environment. He naturally gravitates toward protecting vulnerable people but exhibits deep aggression and suspicion toward anything he perceives as a threat. He firmly rejects Lilith's authority and violently resists the Oankali's influence.

Peter is a highly disruptive human who openly questions Lilith's explanations and challenges her leadership. He views women as commodities to be distributed among the men and attempts to assert dominance by encouraging violence. He completely rejects the idea that they are held by aliens until he is forcefully confronted by the Oankali's reality.

Gabriel is a sharp-minded human who initially forms part of Lilith's small circle of supporters. He understands group dynamics well and warns Lilith when the other humans begin to plot against her. However, his deep-seated need for independence and his inability to accept the Oankali eventually put him at odds with Lilith's methods.

Paul is a human who was rescued by the Oankali as a teenager and has lived among them for decades without returning to Earth. He lives in isolation from other humans, interacting only with his Oankali family. When Lilith meets him, she is thrilled to speak to another human, but quickly realizes that his prolonged isolation has stunted his emotional maturity.

Celene is a timid and highly dependent human survivor. Upon Awakening, she immediately seeks out the strongest male presence for protection, attaching herself to Curt Loehr. She conforms to traditional, subservient roles and relies entirely on others to navigate the strange environment of the ship.

Leah is an aggressively independent human survivor who reacts to her Awakening with immediate hostility. She openly mocks Lilith's claims about aliens and remains highly skeptical of their situation. Despite her initial aggression, she eventually settles into the group dynamic and bonds intensely with the Oankali.

Sharad is a young human boy who does not speak English. The Oankali temporarily place him in Lilith's isolation room, where she teaches him basic language skills and provides him with comfort. He is later removed and placed back into suspended animation.

Tediin is a female Oankali and Jdahya's mate. She provides a welcoming presence in the family unit where Lilith stays and acts as a biological parent to Nikanj. She communicates seamlessly with her family members through their sensory tentacles.

Jean is a volatile and traditionalist human survivor who frequently clashes with Lilith. She holds deeply ingrained sexist views, loudly arguing that it is the women's duty to pair off sexually with the men in the group. She acts as a vocal supporter of Peter's rebellious faction.

Gregory is a newly Awakened human who readily accepts Peter's dominance. Emboldened by the other men, he attempts to drag a woman into his quarters for a non-consensual sexual encounter, prompting a violent intervention from Lilith.

Allison is a human survivor who aligns herself with Lilith's faction. She becomes the target of an attempted sexual assault by the opposing men but physically fights back before Lilith intervenes. She expresses gratitude for Lilith's protection but remains fearful of Lilith's unnatural strength.

Ahajas is a female Oankali who becomes one of Nikanj's adult mates. She is a sibling to Dichaan and forms part of the family structure that will eventually integrate with Lilith. She occasionally speaks to Lilith as a disembodied voice through the ship's walls to provide medical assessments.

Dichaan is a male Oankali and sibling to Ahajas. He acts as Nikanj's male mate, completing their newly formed adult triad. He adjusts the walls in Lilith's living quarters to allow her some freedom of movement.

Wray is an Awakened human who exhibits immediate aggression and a lack of impulse control upon waking. After his initial hostility is subdued, he joins the human survivors in the forest training area, where he struggles with the physical repulsion caused by the Oankali's chemical bonding process.

Derrick is a highly inquisitive Awakened human who refuses to accept his confinement. Aided by Curt and Peter, he climbs into the automated food cabinets to look for the jailers, resulting in his disappearance from the nursery and escalating the group's hostility toward Lilith.

Tehjaht is an ooloi assigned to bond with Peter Van Weerden and Jean Pelerin. It is less perceptive than ooloi like Nikanj or Kahguyaht, failing to recognize Peter's deep-seated humiliation and rage once the tranquilizing drugs begin to wear off.

Yahjahyi is the ooloi assigned to bond with Curt Loehr. It closely monitors Curt's immense hostility and physical resistance, keeping a tight grip on him when his aggression threatens the other Oankali.

Victor is an Awakened human whose confident demeanor encourages others to join Peter and Curt's faction against Lilith. He participates in the group's survival efforts in the forest by catching and roasting turtles.

Beatrice is a human survivor who is deeply fearful of the escalating conflicts within the nursery. She avoids taking action or choosing sides, simply desiring to be left in peace away from the violence of the other humans.

Sam is Lilith's deceased husband from her life on Earth before the nuclear war. He suffered severe brain damage in a car accident that killed their son, remaining on life support for months before passing away. His memory heavily influences Lilith's fears about the Oankali tampering with her brain chemistry.