Indonesian nationality law is regulated by the 1945 Constitution, as amended; various statutes on nationality, as revised over time; as well as international agreements to which Indonesia has been a signatory. These laws determine who is, or is eligible to be, a national of Indonesia. The legal means to acquire nationality and formal membership in a nation differ from the relationship of rights and obligations between a national and the nation, known as citizenship. Indonesian nationality is typically obtained either on the principle of Jus sanguinis, i.e. by birth abroad to at least one parent with Indonesian nationality; or under restricted Jus soli, i.e. by birth in Indonesia. It can also be granted to a permanent resident who has lived in Indonesia for a given period of time through naturalization, as long as the parents are stateless, or unknown.

Acquiring Indonesian nationality Nationality can be acquired in Indonesia through adoption, birth, marriage, or naturalization.

By adoption Children under five years old who have been adopted by at least one parent who is an Indonesian national are eligible for Indonesian nationality. Indonesian children adopted by foreign parents are also considered to be Indonesian until they reach legal majority and choose a nationality.

By birth Individuals who are eligible to be considered Indonesian by birth include:

Persons born within the bounds of the territory or abroad to one Indonesian parent; Foundlings born within Indonesia to unknown parents; Persons born in the territory to parents who are stateless; or Persons who would have become Indonesian, but for the death of the parent.

By marriage Foreign spouses of Indonesian nationals are eligible to choose Indonesian nationality by declaration before the authorities. Five continuous, or ten cumulative years residence in the country is required and the spouse must renounce their nationality of origin or obtain a permit to stay in Indonesia with dual nationality.

By naturalization There are two types of naturalization in Indonesia. Ordinary naturalization requires that an applicant be of legal majority and full capacity. Application fees and documentation are submitted to the Minister of Law and Human Rights. Establishment of a five-year residency, or ten years of intermittent cumulative residence, prior to application is required. Applicants must be in good physical and mental health; be financially self-sufficient; and prove that they have no criminal record which resulted in a jail sentence of one or more years. They must also confirm that they can speak the Indonesian language and provide proof of a basic knowledge of Indonesian civics. Applications are approved at the discretion of the President of Indonesia and if approved, require the applicant to renounce other nationality.

The other type of naturalization is for exceptional merit, including contributions to culture, the environment, humanity, science, sport, or technology, which can or will enhance the nation. Public or private organizations can propose a candidate to the Minister of Law and Human Rights for their extraordinary contributions. Parliament must consider the application and final approval rests with the President of Indonesia.

Loss of Indonesian nationality Indonesians may voluntarily renounce their nationality if they have reached legal majority, have full capacity and will not be rendered stateless by such renunciation. Those who have lost their nationality may generally reacquire it through Ministerial approval or applying for naturalization. Persons may be denaturalized for:

Voluntarily obtaining another nationality or taking an oath of allegiance to another country; Refusing to renounce other nationality when there is an opportunity to do so; Participating in the election processes of another country; Possessing a passport or other official nationality document issued by a foreign nation; Establishing a residence abroad for five or more consecutive years without being in service to the government of Indonesia or failing to declare a desire to retain Indonesian nationality every five years to proper authorities; or Serving in a foreign military or government administrative post without approval of Indonesian authorities. In 2020, the Indonesian government declared that all nationals who had joined the terrorist group Islamic State of Iraq and the Levant (ISIL) would automatically lose their Indonesian nationality and be rendered stateless upon joining the group. The revocation of ISIL fighters' nationality was accompanied by a refusal to repatriate captured combatants and included family members residing abroad with fighters, with the exception of children under the age of eighteen.

Dual nationality Dual nationality is not typically allowed in Indonesia. However, after lobbying from women's rights groups, in 2006, the nationality law was revised to allow children to retain dual nationality until they reach legal majority of seventeen. By that age those who have not chosen their nationality are required to obtain an affidavit for a Limited Indonesian Dual Nationality Passport () to retain dual status. After reaching the age of twenty-one, they must choose a single nationality.

In 2024, government official Luhut Pandjaitan announced that Indonesia may offer dual citizenship to people of Indonesian descent to encourage high-skill workers to move back to the country and boost the economy.

History descent The written history of Indonesia encompasses 800 years, spanning some 400 now autonomous regions and including in the boundaries of the archipelagic country around 18,000 islands. For centuries before European colonization, the various islands were linked either by trade or familial ties and at various times shared rulers.

Early monarchies and sultanates (400–1511) From the 2nd and 3rd centuries of the Common Era, Indian cultural practices slowly expanded into Southeast Asia. Art, governance structures, and religion were absorbed and modified by the early inhabitants of the islands, Austronesian peoples, who lived in scattered tribal settlements, which were united by kinship ties. Physical isolation and limited communications created difficulties in maintaining centralized authority over vast distances, thus typically governance existed in a system of limited kingship with autonomous regional leaders to direct affairs in their territories. In exchange for their allegiance, local populations received protection, prestige, and a share of wealth from their leaders. As states emerged, from the 6th to 9th centuries, their rulers followed imported religions like Hinduism and Buddhism. Though they did not follow India's caste system, the early kingdoms used the terminology of Indian courts to delineate the power divisions within their territory. These kingdoms were founded on trade relationships and some established tributary relationships with China to facilitate both commerce and protection ties. Trade routes between China and the Middle East were maintained primarily by use of the sea routes through the waters of the archipelago and Arabic envoys stationed with the Chinese court acted as emissaries to the kingdoms in the archipelago. By the 11th century Buddhist and Hindu kingdoms began to decline and slowly be replaced by rulers from the growing Islamic movement from the 12th century. Between the 13th and 16th centuries, Islamic sultanates had spread from northern Sumatra to the eastern part of the archipelago.

Portuguese period (1511–1605) Portuguese merchants, eager to sever the monopoly Muslim merchants and their Venetian commerce-brokers held over the spice trade, were encouraged by Prince Henry the Navigator to use naval war to gain control of the archipelago. Afonso de Albuquerque sailed to India in 1503 and conquered Goa in 1510, establishing a trading base for the Portuguese. From Goa, Albuquerque sailed to Malacca with over a dozen ships and conquered the sultans there in 1511. Immediately, Francisco Serrão launched an exploration from Malacca to find the spice islands to the east, but was shipwrecked in 1512. The survivors made their way to Ambon Island and endeared themselves to the local ruler by attacking a rival. Hearing of the incident, the sultans of the neighboring islands, Tĕrnate and Tidore, sought to build alliances with the Portuguese. With the Portuguese came Christian missionaries, notably Francis Xavier, one of the founders of the Jesuit Order, who introduced and spread Christianity to the archipelago.

In 1521, the () of 1446 were replaced by the Ordinances of Manuel I (). Under the ordinances, courts were granted the ability to interpret common law, statues, and custom creating opinion for newly arisen situations. In areas of the kingdom without established High Courts, common law and local custom prevailed. Nationals were those born in the territory and leaving the territory without permission of the sovereign was grounds for denaturalization. In 1603, the () established that Portuguese nationals were children born on the Iberian Peninsula or adjacent islands, Brazil, or to an official in service to the crown in the Portuguese possessions of Africa or Asia, whose father was a native of Portugal, or whose mother was a native of Portugal and was married to a foreigner who had established domicile in Portugal for a minimum of ten years. Those who were not in service to the crown in the colonies (except Brazil) were not considered to be Portuguese.

The Portuguese period on the archipelago fundamentally changed the Asian trading system. The Portuguese dismantled the system of policing the Straits of Malacca to protect commercial vessels and dispersed the trade centers to various ports. The period was characterized by conflict between various sultans and the Portuguese. Islanders quickly mastered navigational and military technology the Portuguese had brought, and the Portuguese were never able to successfully dominate trade. Dutch merchants had acted as middlemen in selling Portuguese spices to Europe, but during the Dutch Revolt (1566–1648) against Spain, their access to spices was curtailed by the Iberian Union of Spain and Portugal. Recognizing the weak position of the Portuguese in the archipelago, Cornelis de Houtman led an expedition in 1595 to Java. Though he lost most of his ships, the profit gained from the spices gathered during the trip spurred other Dutch voyages. In 1598, the Dutch parliament proposed a merger of Dutch trading agents and in 1602, the Dutch East India Company was formed. In 1600 the Dutch won a naval battle at Ambon and joined the Muslim Hituese in an alliance against Portugal. The Portuguese regrouped but in a second battle in 1605, surrendered to the alliance.

Dutch period (1605–1949)