Assimilado or assimilada (if female), literally "assimilated", was a status assigned from the 1910s to the 1960s to those African subjects of the colonial Portuguese Empire who had reached a level of "civilization", according to Portuguese legal standards, that theoretically qualified them for full rights as Portuguese citizens. Portuguese colonizers claimed the goal of their assimilation practices to be the "close union of races of different degrees of civilization that help and support each other loyally"; however, this notion of a "close union" differed from its practical application in the cultural and social spheres of the colonies of Portuguese Angola, Portuguese Mozambique and Portuguese Guinea.

Portugal, along with France, was one of the only Africa colonizers which introduced the idea of assimilation of the colonized people into the population of the motherland. Although Portugal was one of the first European presences in Africa, Portuguese influence remained coastal and trade-oriented until the late 1800s, early 1900s; "control of the hinterland was non-existent, even in the 19th century", but with increased competition between European powers, the Portuguese "became more aggressively engaged", and adopted ideals of assimilation.

Portuguese colonial laws had general and specific contexts for each of the colonies of Angola, Mozambique, and Portuguese Guinea; "some of the legislation and policies the Portuguese implemented reflected their empire-wide preoccupations, [while] others reflected their concerns specifically with the colony". In Angola, for instance, the procedure started with the applicant proving his ability to speak and write Portuguese. He then had to show that he had a source of income and pay a fee. The applicant also had to furnish a number of documents and certificates. The Organic Charter of Guinea enacted in 1917 also stipulated that the applicant must show proof of dedication to the interests of Portugal. In other African colonies, authorities required that natives live in a "European manner." One historical account even cited a covert surveillance system that monitored assimilated parents to ensure they did not teach their children any of the African languages.^{[citation needed]}

The Department of Native Affairs, which was formed in 1914, had empire-wide effects; its purpose was 'to classify the African population into "civilized" or assimilated (assimilado), and "non-civilized" or nonassimilated (não-assimilado) to facilitate recruiting and to designate who were collaborators', which effectively initiated the legal category of assimilado throughout the colonial empire. Two laws, the Estatuto Politico, Civil, e Criminal dos indigenas das colónias de Angola, Guiné e Moçambique (Political, Criminal, and Civil Statute of the Natives of Angola, Guinea, and Mozambique) of 1926, which was revised as the Acto Colonial (Colonial Act) of 1930, and the Lei Orgânica do Ultramar (Organic Law of the Colonies) of 1954, explained the 'subordinate but vital role the colonies and colonial peoples were to play in the new Portuguese Empire, and the duty of the government towards the "native" populations'. The Portuguese colonial empire hoped that the assimilados would set an example for the rest of the Black Africans of the colonies to shift towards civilization; the Portuguese thus afforded some of the assimilados governmental roles, "as long as they were kept outside of 'anarchic democratic structures'."

Education and religion both were integral parts in the process of assimilation and the qualification for the status of assimilado. Beyond just the studying of Portuguese language and culture, the actual adoption of Portuguese culture as one's own, including the adoption of Christianity and the emulation of European and Portuguese ideals, was integral. Only through being Portuguese in every facet of life, from language to schooling to personal association, could one be considered a useful tool in society, and thus be afforded special rights.

Although the Portuguese conceded certain written rights to the assimilados, because of the authoritarian nature of the Portuguese government, "the status of 'assimilado' did not give these Africans explicit political rights". The Portuguese thus did not fear that assimilados would be "potential competitors" that might endanger "their predominant position". Since "the Portuguese colonial system could utilize more authoritarian instruments", the government could give assimilados jobs in the government, thus affording a small amount of protection to the assimilados, and proving to the international world the accommodating nature of their colonial rule, while not having to feel threatened by the educated assimilados in administrative jobs.

The Portuguese were certainly not the only colonizing power to stress a "civilizing mission" (missão civilizadora) as the central tenet of colonial expansion; the Portuguese elite, alongside many in power in most of the colonizer countries, believed that their country's "presence was a means to advance 'primitive peoples', to bring them knowledge and some kind of protection and welfare". However, the additional notion of assimilation adds a specific element to the motivations of Portugal's colonizing government. The notion of lusotropicalism, which posited a "multicultural image (lusotropicalismo), with its emphasis on the mutuality and intermingling of African, Afro-Portuguese (creole), and Portuguese institutions" was introduced as New State propaganda displaying the ideal Portuguese colonialism, but the reality of Portugal's colonial institutions lay far from that ideal.

In this perspective, Portuguese rhetoric, which stressed the luso-tropical myth of a particular affinity to non-European cultures, including the emergence of mestiço populations and an easy way to assimilation, appears as pure and voluntary hypocrisy. The myth would have been created to hide the abuses inherent in the colonial system.