To become a citizen, you must fall into one of the following categories:

Citizenship by origin: you are a child born to a Nauru citizen on or after January 31, 1968, or a child born to a Nauru citizen and a resident of the Pacific Islands (Cook Islands, Fiji, Kiribati, Republic of the Marshall Islands, Federated States of Micronesia, Nauru, Niue, Palau, Papua New Guinea, Samoa, Solomon Islands, Tonga, Tuvalu, and Vanuatu), and neither parent has stated within seven days of birth,  that you are not a citizen of Nauru.

By birth: being born on the territory of Nauru does not automatically grant citizenship. Citizenship is automatically granted only to those persons who were born in this territory, but otherwise would be stateless persons.

Citizenship through marriage: you are a foreigner who marries a Nauru citizen.

Citizenship by naturalization: you do not belong to any of the above categories, but you have lived here for a long time. According to the provisions, you must meet certain requirements to obtain this citizenship.

Persons entitled to naturalization include:

• Legal spouse of a Nauru citizen;
• Underage child, legally adopted by ​at least one of the parents from Nauru, which came into force after the court issued an adoption decision; or 
• Persons who can confirm the ownership of land through the biological origin of a Nauru citizen.

Dual citizenship is not recognized here, except in cases where a Nauru woman receives second citizenship after marriage to a foreigner.

Requirements

To become a citizen and live here, in addition to the necessary documents, you must meet the following criteria:

• Live on the island for at least five years;
• Be fluent in the Nauruan language;
• Have a police clearance;
• Availability of a residence permit;
• Be stateless.