The demographics of Nauru, an island country in the Pacific Ocean, are known through national censuses, which have been analysed by various statistical bureaus since the 1920s. The Nauru Bureau of Statistics have conducted this task since 1977—the first census since Nauru gained independence in 1968. The most recent census of Nauru was on 30 October 2021, when population had reached 11,680 people. The population density is 554 inhabitants per square kilometre (1,430 inhabitants/sq mi), and the overall life expectancy is 63.9 years. The population rose steadily from the 1960s until 2006 when the Government of Nauru repatriated thousands of Tuvaluan and I-Kiribati workers from the country. Since 1992, Nauru's birth rate has exceeded its death rate; the natural growth rate is positive. In terms of age structure, the population is dominated by the 15–59-year-old segment (57%). The median age of the population is 21.6, and the estimated gender ratio of the population is 101.8 males per 100 females.
Nauru is inhabited mostly by Nauruans (92.1%), while minorities include those from Kiribati (2.4%), Fiji (2.2%), Australia (1.2%) and other (2.1%). The demographic history of Nauru is marked by several migrations: the area was first inhabited by Micronesian people about 3,000 years ago. The first European to find the island was John Fearn in 1798. Then, the country was annexed by Germany in 1888. The next major population change was when Japanese occupied the island during World War II in 1942. During this time, the Japanese deported several thousands of Nauruans to other islands. In the 1960s, the country gained independence, where the percentage of Nauruans started to increase. The most recent demographic switch was in the 2000s, when the government repatriated several groups of non-Nauruans from the country.
