The population of the country almost doubled during the twentieth century (+91%), but the pattern of growth was extremely uneven due to large-scale internal migration from the rural North to the industrial cities of Lisbon and Porto, a phenomenon which happened as a consequence of the robust economic growth and structural modernisation, owing to a liberalisation of the economy of the 1960s.

High fertility and birth rates persisted until the 1980s, after which they started to dramatically decline, leading to rapid population aging.

Due to decrease in emigration and increase in immigration in the late 1990s and early 2000s the total population reached its peak in December 2009, standing at 10,573,479.

The Portuguese people are mainly a combination of ancient paleolithic populations, and the proto-Celtic, Celtic, and the para-Celtic Lusitanians.

Some other groups, like the Romans, Germanic (Visigoths, Suevi, Buri, Alans and Vandals) and later the Moorish (Arabs and Berber), Sephardic Jewish, and the French also passed through the country.

[7][8] Portuguese is spoken throughout the country, with only some villages near the northern municipality of Miranda do Douro speaking Mirandese, locally recognised as a co-official language.

[18] Source: UN World Population Prospects[35] As of 2023, Portugal had two significant agglomerations: the political metropolitan areas of Lisbon and Porto – Grande Área Metropolitana de Lisboa (3.0 million) and Grande Área Metropolitana do Porto (1.8 million).

[48] Since the independence of the former African colonies, Portugal saw a steady immigration from Africa, most notably Cape Verde, Angola and Guinea-Bissau, but also São Tomé and Príncipe, Mozambique and former Portuguese India in Asia.

Portugal saw migration waves due to labor shortages since 1999, first from Eastern Europe (1999–2002), in two distinctive groups, a Slav (Ukraine, Russia and Bulgaria) and an East Latin (Romania and Moldova), that stopped and started declining as the labour market became saturated.

[49] There is also a significant number of elderly Western European residents in search of quality of life, namely from the United Kingdom, France, Germany, the Netherlands and Belgium.

Discrimination against persons with disabilities in employment, education, access to health care, or the provision of other state services is illegal.

[55] Other autochthonous languages spoken include: Religion in Portugal (Census 2021)[65] The great majority of the Portuguese population belongs to the Roman Catholic Church.