Almost all Gabonese are of Bantu origin. Gabon has at least forty ethnic groups with differing languages and cultures. The Fang are generally thought to be the largest, although recent census data seem to favor the Nzebi. Others include the Myene, Kota, Shira, Puru, and Kande. Ethnic boundaries are less sharply drawn in Gabon than elsewhere in Africa. There are also various Pygmy peoples: the Bongo, Kota, and Baka; the latter speak the only non-Bantu language in Gabon.

Most ethnicities are spread throughout Gabon, leading to constant contact and interaction among the groups. Intermarriage between the ethnicities is quite common, helping reduce ethnic tensions. French, the language of its former colonial ruler, is a unifying force. The Democratic Party of Gabon (PDG)'s historical dominance also has served to unite various ethnicities and local interests into a larger whole. More than 10,000 native French live in Gabon, including an estimated 2,000 dual nationals.

It is estimated that 80% of Gabon's population can speak French, and that 30% of Libreville residents are native speakers of the language. Nationally, 32% of the Gabonese people speak the Fang language as a mother tongue.

In October 2012, just before the 14th summit of the Organisation internationale de la Francophonie, the country declared an intention to add English as a second official language, reportedly in response to an investigation by France into corruption in the African country, though a government spokesman insisted it was for practical reasons only. It was later clarified that the country intended to introduce English as a first foreign language in schools, while keeping French as the general medium of instruction.