The novel's protagonist, Obi Okonkwo, is a young man who has returned to Nigeria after having studied in England. The fact that he went to England to study and has returned puts him a peculiar position, one in which he will have to face the issues of a man torn between his own country and what he has learned in the hands of those who have colonized his country (the English). The novel follows his idealistic beginnings to his unfortunate end, an end in which he is put on trial for taking a bribe.
Obi's fiancée, Clara is a young Nigerian woman whom Obi met, originally, at a dance in London and later on the boat ride back to Nigeria. Clara is not intellectual but strong-minded. She has also studied abroad and has become a nurse. The main conflict with Clara is that she is an osu, which means she is an outcast that is not allowed to marry Obi. This fact causes the main struggle between Clara and Obi regarding their relationship and their marriage.
Obi's father, Isaac Okonkwo, is a Christian. He had left home at an early age, against the will of his father, because he wanted to join the other Christians. Isaac's Christianity is the most important aspect of his life, and it colors most everything he does and says.
Obi's mother, Hannah, is another woman of strong-will in the novel, with whom Obi has a special relationship. It is Obi's mother that refuses to allow him to marry Clara by threat of her own suicide. However, it was also Hannah that shared folk stories with Obi—stories that he could share at school and for which he loved her. They also have a special bond of blood, according to a story in which his mother cuts herself with a blade from his pocket.
A friend of Obi's and a clerk in the Survey Department, Joseph is an important character because of his actions. He gives Obi a place to stay and an ear to listen whenever Obi needs one. However, it is Joseph who tells the Umuofia Progressive Union about Clara being an osu. Still, Joseph may be doing this because he believes it best for Obi not to marry Clara. And, later, he acts as a friend, once again, when he brings Obi beer to help entertain the people who attend the funeral gathering.
Another friend of Obi's, Christopher, unlike Joseph is educated. He is very much like Obi in terms of education, but Christopher is very different in attitude. He is more pragmatic than Obi and less of an idealist. He believes he knows how to live in the Nigerian world of the late 1950s, and he thinks he understands the balance he must possess in order to live in between two very different cultures.
Obi's boss at the Civil Service, Mr. Green is an old Englishman, accustomed to the ways of colonialism and the mindset of such. He believes that the English brought education and civility to Africa. He also believes that the African is, by nature, corrupt and even implies an inherent laziness in Africans. Nevertheless, he pays for the school fees of his steward's sons. We are told that he works very hard for the country and that he is not all together a "bad man," as Miss Tomlinson (Mr. Green's secretary) likes to remind Obi.
The administrative assistant at Obi's office, Mr. Omo, is what Obi calls an "old African." Accustomed to the rule of the English, Mr. Omo is submissive to his boss Mr. Green and respectful of "old ways." He has worked for the Civil Service for thirty years and has a son studying law in England. His physical description is also unappealing—he is said to have black teeth from cigarettes and kola nuts, and one of those teeth were missing from the front.
Mr. Green's secretary, Marie, is kind to Obi. Marie often claims what a strange man Mr. Green is and, on other occasions, defends the same Mr. Green. She, like Mr. Green, represents the presence of the English in Nigeria.
The Minister of State, Sam Okoli is a good looking and popular politician. He becomes friends with both Obi and Clara, through Clara's connection to him. It is from Sam that Obi borrows the money for Clara's abortion.