Ugwu – The novel starts and ends with Ugwu. He is a village boy from Opi who later becomes a servant in Odenigbo’s house. Under Odenigbo and Olanna’s guidance, Ugwu is able to continue his education and his literary skills progress throughout the novel. He tries to maintain in contact with his mother and sister, Anulika, back in his home village, and is constantly look at for his mother’s health and wellbeing. His free time is often dominated by his love interests, which include Nesinachi, Enberi, and Chinyere. His life is violently interrupted when he is forcibly conscripted into the Biafrain Army. There, he witnesses and participates in gruesome battle and a rape.
Odenigbo – Odenigbo starts the novel as Professor of Mathematics at Nsukka University. His strong opinions result in some characters labeling him as a “revolutionary.” He favors socialism and tribalism to capitalism and Pan-Africanism or nationalism. After the war forces him to vacate his position at Nsukka University, Odenigbo becomes active in the war cause under Manpower Directorate . His personal life is dominated by his relationship and later marriage to Olanna. He is the father of Baby, though Amala, not Olanna, is Baby’s mother. Odenigbo also has a strong, albeit turbulent, relationship with his mother. “Mama” affects his relationship with Olanna, and Mama’s death starts Odenigbo on a dark path of alcoholism and depression.
Olanna – Olanna is one of three characters through which the novel is told (the others being Ugwu and Richard). She is the daughter of Chief Ozobia and twin of Kainene. Olanna was raised in Nigeria, and later attended university in the United Kingdom. She is described as “illogically beautiful,” and her appearance often dictates how others treat her. For example, her parents try to offer sex with her as a bribe to help secure business deals. Consequently, her connection with her parents is weak and she gravitates towards her Aunt Ifeka and Uncle Mbaeka in Kano. Odenigbo is first her boyfriend and later her husband, and she is the adopted mother of Baby. Mohammed is her ex-boyfriend. Professionally, she is a Professor of Sociology at Nsukka University before the war begins. She later works as a school teacher in Umuahia and finally helps her sister care for refugees in Orlu.
Kainene – Kainene, Olanna’s twin, seems to be at first very different from Olanna. She is the type of strong-headed woman, independent, cold, very calculated. Kainene lives in Port Harcourt where she runs her father’s business. Her father, very proud of her, tells one of his friends that she is “not just like a son, she is like two.” In the beginning of the war, she is a war profiteer. However, after she witnesses the war’s cruelty, she changes completely as a character and instead of running her father’s business, she runs a refugee camp. She remains fearless and in the end decides to trade with the enemy, putting her life at risk.
Richard Churchill – Richard is an English writer who comes to Nigeria to explore Igbo-Ukwu art. At first he associates with other expats, especially Susan who becomes his girlfriend. However, once he meets Kainene at one of the parties Susan drags him to, he becomes fascinated with her. Richard moves to Nsukka where he teaches at the Nsukka University and attempts to write a book about the Igbo-Ukwu art. Olanna invites him to be part of Odenigbo’s circle of intellectuals. Richard is glad to witness Biafra’s birth, thinking it would actually make him Biafran. He starts writing a book about the war, but soon realizes that it is not his story to tell. Adichie has said in an interview that the idea of Richard came from Frederick Forsyth, a staunch supporter of Biafra: “Richard isn’t at all like him, of course, but just the sense of an Englishman who became more Biafran than Biafrans themselves, was really an idea that came from him, Forsyth.” 
Ugwu’s Aunty – Cleaner at Nsukka University, she introduces Ugwu to Master Odenigbo.
Anulika – Anulika is Ugwu’s sister. She is preparing to get married before the war, but a war-time tragedy changes her plans.
Nesinachi – Ugwu’s first crush from his village of Opi. Ugwu and Nesinachi reconnect after the war.
Ugwu’s mother – Ugwu’s mother suffers from illness in Ugwu’s home village of Opi. She seeks treatment in Nsukka with Odenigbo’s help. Ugwu often worries about her during the war.
Miss Adebayo –Yoruba professor at Nsukka University. Sexual tension between Miss Adebayo and Odenigbo create an awkward relationship between Miss Adebayo and Olanna. As the war starts to break out, Miss Adebayo’s ethnicity creates a gap between her and other professors.
Dr Patel – Indian Professor at Nsukka University. Dr. Patel is a friend of Odenigbo and Olanna.
Professor Lehman – American Professor at Nsukka University. Professor Lehman’s views are often criticized by Odenigbo.
Professor Ezeka – Professor at Nsukka University who later becomes Director of Mobilization in the Biafran Army.
Okeoma – A friend of Olanna and Odenigbo in Nsukka. Okeoma is a renowned poet, as one point called, “the voice of our generation.” He cites Olanna as his inspiration. Okeoma later becomes an officer in the Biafran Army and stops writing poems.
Edna – Olanna’s neighbor in Nsukka. Edna is an African American woman with strong opinions on racial and gender injustice.
Jomo – Jomo works as the gardener at both Richard’s house and Odenigbo’s house in Nsukka. He is one of Ugwu’s first friends in Nsukka and is also often feuding with his rival, Harrison.
Harrison – Richard’s houseboy. Harrison’s talkative nature at first annoys Richard, and later gets him into trouble.
Chinyere – Works in a house near Master’s in Nsukka. Maintains late night visits with Ugwu until the war starts.
Mama (Odenigbo's mother) – A village woman from Abba. She is opposed to the relationship between Odenigbo and Olanna because they are not officially married (no bride price paid yet) plus Olanna is an unnatural woman.
Amala – A village girl who works for Mama, Odenigbo’s mother. To break up Olanna and Odenigbo Mama makes Amala sleeps with Odenigbo. Amala gets pregnant but after giving birth, she refuses to take the child and sends her back to Mama.
Chief Okonji – Friend of Olanna and Kainene’s parents. Chief Okonji claims a romantic interest in Olanna, but is thoroughly rebuffed by Olanna.
Chief Ozobia – Prominent businessman in Lagos and father to Olanna and Kainene. Chief Ozobia manipulates his daughters for financial benefit. He also keeps a mistress, and eventually leaves Nigerian during the war.
Olanna and Kainene’s Mother – Chief Ozobia’s wife and mother of Olanna and Kainene. She does not have a strong relationship with her daughters, and her marriage with Chief Ozobi might be described as a pretense.
Uncle Mbaezi – Olanna’s uncle, he is the brother of Olanna’s mother. He lives with his family in Kano where he founded the Igbo Union Grammar School.
Aunty Ifeka – Uncle Mbaezi’s wife. Aunty Ifekagives guidance to Olanna, who isn’t very close to her own mother.
Arize – Olanna’s cousin, she is Uncle Mbaezi and Aunty Ifeka’s daughter. Arize is eager find a husband and get married. Like her parents, she looks up to Olanna.
Mohammed – Olanna’s ex-boyfriend. He is a handsome Hausa man. Even after she leaves him for Odenigbo, they remain on good terms and she frequently visits him until the war starts. During the war, writes her letters but they feel very distance.
Baby – Olanna and Odenigbo's daughter. Amala is Baby's birth mother, but refuses to keep her. When Olanna sees her, she decides to adopt her. Baby’s real name is Chiamaka, which means "God is beautiful." Kainene picked it but it is rarely used.
Susan – Initially Richard’s girlfriend. She lives in Nigeria but mainly associates with other expatriates or upper class Nigerians. Her racism towards Nigerians as well as her possessiveness towards Richard emerge periodically throughout the novel.
Major Madu – Lifelong friend of Kainene. Major Madu serves in first the Nigerian and later Biafran army. He and Richard’s relationship is strained due to the uncertainty of Madu’s role in Kainene’s life.
Special Julius – Army contractor. He becomes a frequent visitor of Odenigbo when they are in Umuahia.
Ekwenugo – Member of the Science group in the Biafran army. Ekwenugo meets Olanna and Odenigbo in Umuahia.
Mrs Muokelu – Co-teacher with Olanna at Umuahia. Olanna finds Mrs. Muokelu as manly and slightly judgmental. Mrs. Muokelu eventually stops teaching and starts trading across enemy lines.
Okoromadu – An old acquaintance of Olanna’s, Okoromadu helps her get emergency supplies for baby in Umuahia.
Eberechi – Ugwu’s love interest in Umuahia. Eberechi is exploited for her parents’ benefit.
Alice – Odenigbo and Olanna’s neigbhbor at their second place of residence in Umuahia. Alice is seeks refuge in Umahia after being tricked by an Army Colornel. She is known as a recluse and avid pianist. Mystery shrouds her relationship with Odenigbo.
Father Marcel – Helps coordinate refugee relief with Kainene in Orlu. Father Marcel is later accused of impropriety by some of the refugees.
High-Tech – A young soldier and leader of Ugwu’s reconnaissance unit. High tech’s name refers to his commanders claiming he is more useful than a “high technology spying gadget.”