Of the island's 13,048 residents, 58% are Nauruan, 26% other Pacific Islanders, 8% Chinese and 8% Europeans. The official language of Nauru is Nauruan, a distinct Pacific island language. English is widely spoken and is the language of government and commerce.
The main religion practised on the island is Christianity (two-thirds Protestant, one-third Roman Catholic). There is also a sizable Bahá'í population (10 percent of the population). The Constitution provides for freedom of religion; however, the government restricts this right in some circumstances, and has restricted the practice of religion by The Church of Jesus Christ of Latter-day Saints and members of Jehovah's Witnesses, most of whom are foreign workers employed by the Nauru Phosphate Corporation.
An increased standard of living since independence has had some negative effects on the population. Nauruans are among the most obese people in the world, with 90% of adults overweight. Nauru has the world's highest level of type 2 diabetes, with more than 40% of the population affected. Other significant diet-related problems on Nauru include renal failure and heart disease. Life expectancy has fallen to 58.0 years for males and 65.0 years for females.
Literacy on the island is 97%, education is compulsory for children from six to 15 years of age (Years 1–10), and two non-compulsory years are taught (Years 11 and 12). There is a campus of the University of the South Pacific on the island; before the campus was built, students travelled to Australia for their university education.