The population of Kiribati was around at 94,149 in 2001, giving the nation a population density of 116 persons per sq km (301 per sq mi). The overwhelming majority of the people are of Micronesian descent and are known as I-Kiribati. There are also very small minorities of Polynesians and non-Pacific Islanders. English is the official language of Kiribati, and many I-Kiribati speak it in addition to their native language, Gilbertese, an Austronesian language. Christianity predominates in Kiribati: about half of the population is Roman Catholic, and about 40 % is Protestant. There are also small groups of Seventh-day Adventists, Baha’is, and Mormons.

Kiribati includes Kiritimati ,the largest coral atoll in the world, and Banaba, one of the three great phosphate islands in the Pacific. Except on Banaba, very little land is more than three meters above sea level. The original inhabitants of Kiribati are Gilbertese, a Micronesian people. around 90% of the population of Kiribati lives on the atolls of the Gilbert Islands. Owing to an annual population growth rate of around 2.5% and severe overcrowding in the capital on South Tarawa, a program of migration has been implemented to move nearly 5,000 inhabitants to outlying atolls, mainly in the Line Islands. The Phoenix Islands have never had any permanent population. A British effort to settle Gilbertese there in the 1930's failed due to deficiency of water. A new program of settlement to the Phoenix Islands was begun in 1995.