Chinua Achebe wrote his classic novel Things Fall Apart in response to Joseph Conrad's popular novella Heart of Darkness, which portrayed Africans as uncivilized savages and ignorant, dangerous cannibals.

Throughout Things Fall Apart, Achebe challenges prejudiced European beliefs regarding Igbo civilization and society by depicting a rich, organized culture with traditions, rituals, and ceremonies. He illustrates traditional Igbo culture by vividly describing The Feast of the New Yam, the Week of Peace, and numerous other ceremonies, and he elaborates on the complex religious views of the Umuofia villagers. The Igbo have a polytheistic, patriarchal society which honors their ancestors and bestows titles to successful men. They are also deeply religious and obey the commands of the Oracle of the Hills and the Caves.

In Umuofia, village ancestors are revered, and the egwugwu represent the spirits of the nine villages. The egwugwu are also judges and preside over disputes. Achebe continues to demonstrate the civility of Igbo culture by portraying its judicial system as fair, balanced, and practical. He also illustrates meaningful common rituals like the breaking of the kola nut to begin important meetings and the offering of palm-wine to guests.

Achebe elaborates on the complex marriage customs, which involves a bride-price, a Uri ceremony, and an isa-ifi ceremony. Characters like Obierika are also portrayed as intelligent, rational, and tolerant, which undermines prejudiced views regarding Africans. Overall, Achebe challenges the belief that Africans are uncivilized savages by depicting a rich, civil society, which significantly differs from the culture of western Europe.

This depends on your point of view. The British colonial administrators in the late nineteenth and early twentieth centuries tended to use the word "civilized" to reflect their own value system. They tended to think that "civilized" meant white Christians dressing in European style and having a highly literate European style of bureaucracy. Of course, the Igbo were not British and did not fit that model. The Igbo recognized cultural differences and the diversity of different peoples, as seen when when Achebe states:

The world has no end, and what is good among one people is an abomination with others.

Even though the Igbo were not "civilized" from the narrow viewpoint of the British in the novel, the Igbo had their own civilization, with their own religion, oral traditions, modes of governance, and customs. The Igbo thus were what an objective reader would call civilized. Much of the tragedy of the book deals with the breakdown of Igbo civilization as a result of colonialism and how Igbo individuals are caught between the two cultures. 

The shortest answer is yes. To the question of whether or not the Igbo people are "civilized" in Things Fall Apart, we simply need to ask if the Igbo have social rules that govern behavior, distinguishing proper behavior from improper and providing a framework for social/population growth. 

Since the concept of civility is basically defined in accordance with the presence of social rules and the Igbo's sometimes elaborate and often strictly enforced social rules play a central role in the text, we can say with certainty that the Igbo people are civilized. 

For example, the head of a household honors any male guest by praying over and sharing a kola nut with him, offering the guest the privilege of breaking the nut. They dank palm-wine together, with the oldest person taking the first drink after the provider has tasted it (eNotes).

If the English or Japanese practices of taking tea/tea rituals are often seen as standard, symbolic examples of civilized behavior, we can draw a strong and direct connection from tea rituals to those of the kola nut.

Social norms like this one and many others help to define the traditions and social life of the Igbo culture. Other norms regulate marriage, trade, agriculture and conflict. 

The conflict of colonialism that occurs in the late portions of the novel then becomes one of a clash of civilizations - not a conflict between one civilized people and one uncivilized people. 

The question of civilization is central to the conflict between the Igbo and the British. It goes back to Kipling's "White man's burden"- the idea that Europeans and Westerners in general (and the British in particular) were responsible for "civilizing" and converting natives on other continents, who were in turn called savages. This is in part  why Africa was known as "the dark continent." Because the societies were structured differently from those in Europe, they were not seen as civilized in their own right.

The Igbo villages demonstrate each aspect of what is considered civilization: systems of government, economy, and justice, social/communal roles and ceremonies, communication/diplomacy with other societies, etc. In addition, they have established religion, art, and elaborately developed oral storytelling. That is one purpose in Achebe's writing, to bring knowledge of this culture to a wider audience, and to combat the stereotype of pre-colonial Africa as "uncivilized."

Were the Ibo people in Chinua Achebe's Things Fall Apart civilized?

Definitions of “civilized” can vary according to individual perceptions of alien cultures, but one would be hard-pressed to conclude that the Ibo, as described in Chinua Achebe’s Things Fall Apart, were not “civilized.”  On the contrary, while the indigenous tribes of Nigeria, the setting for Achebe’s story, are not depicted driving Buicks and engaging in rituals and celebrations familiar to Western cultures, the Ibo clearly represent an organized society with commonly-accepted customs and a hierarchical structure that placed certain among them in leadership positions (“We have men of high title and chief priests and the elders,” the Ibo explain to Western missionaries inquiring as to the identity of their king and being and informing these foreign visitors that no such exalted position existed).  The Ibo of Things Fall Apart are very much civilized in the sense that they accept limitations on individual conduct for the good of the tribe, and respect those of superior achievement and character.  One quote from the book that suggests a people far too admirable of character to be considered anything other than civilized occurs in Chapter One, as Achebe’s narrator describes a crucial distinction between two characters, Okoye and Unoka, he notes that, while both were musicians, Okoye was not a failure who left a trail of debts everywhere he went.  When Okoye visits Unoka in an attempt at convincing Unoka to repay his debt to him, Achebe describes the scene as follows:

“Having spoken plainly so far, Okoye said the next half-dozen sentences in proverbs.  Among the Ibo the art of conversation is regarded very highly, and proverbs are the palm-oil with which words are eaten.”

Achebe means to convey the sense that these are a people every bit of civilized as the whites who come to convert them and occupy their land.  In Chapter Sixteen, the narrator, describing an encounter with a European, observes that the “[t]he white man was also their brother because they were all sons of God.”  In conclusion, the Ibo, as depicted in Things Fall Apart, are indeed civilized.