The population's spatial distribution and composition

Unequal distribution of the population is another important demographic characteristic. Almost two thirds of the population today live in a little more than one third of the territory of Croatia. The greatest population concentration is in the City of Zagreb, where 19% of the population of Croatia lived in 2019, and which has exhibited increasing population density for several decades. The smallest concentration is in the Lika-Senj County, where only 1.1% of the population lives, and where the population density has been falling for over 30 years.

In general, population density is lowest, and decrease highest, in rural areas and parts of the country with poor transport communications, such as highland areas (Lika, Gorski Kotar), the islands, the Dalmatian hinterland, distant and inaccessible parts of central Croatia and, more recently, Slavonia, particularly after the Homeland War. Therefore, population density in Croatia today is uneven and patchy. A relative increase in the population, and thus population density, has been noted around the largest cities, Zagreb, Split and Rijeka, primarily thanks to population growth in their satellite towns, and also in some medium-sized coastal towns in Istria, Kvarner and Dalmatia. A trend towards seasonal or permanent relocation, particularly by the retired population, from large cities to second homes, particularly on the coast, has also been observed.

Croatia is a moderately urbanised country. Almost 60% of the population lives in towns, and 25% of the population lives in the four largest cities (Zagreb, Split, Rijeka and Osijek). After the Second World War, intensive industrialisation led to a mass exodus from the villages to the towns, which have developed rapidly, while the villages have lagged behind.
Motovun, in Istria, an example of a hilltop village. The coastal area is characterised by compact settlements all along the shoreline, while in the higher parts, such as Istria, there are hilltop settlements with a long urban tradition.
Zmajevac village strings out along the road in Baranja. In the plain areas of Pannonia, villages tend to string out along the road, while in the hilly interior, such as Hrvatsko Zagorje, straggling villages are predominant.

According to ethnic composition, Croatia is a particularly homogenous country; today, Croats make up 91.63% of the population. The largest national minority is the Serbian minority, representing 3.2% of the population. The other more tjan 20 national minorities have far fewer members.

Serbs have been immigrating to Croatia for a fairly long time, beginning in the 16th century. They settled in the area of the former Military Border (Lika, Banova, Kordun, parts of northern Dalmatia, eastern and western Slavonia), and later also came to larger towns. The proportion of Serbs has fallen sharply due to emigration caused by the events of war in the 1990s. After the Homeland War, a portion of them returned to Croatia.

The Bosniacs (formerly known as Muslims) are the third largest ethnic group and constitute 0.62% of the population. They have mostly settled in towns. After the Austro-Hungarian occupation of Bosnia and Herzegovina in 1878, they came in greater numbers, and also after the Second World War (particularly during the 1960s and 1970s, for economic reasons). The Italian minority (0.36%) mostly lives in Istria and Rijeka, with some in western Slavonia. Hungarians make up 0.27% of the population, and live in the villages of eastern Slavonia and Baranja, along the border with Hungary. Slovenes (0.2%) live throughout Croatia, though their numbers are somewhat higher along the Croatian-Slovenian border, in Istria, Rijeka, Opatija, Gorski Kotar, Zagreb and other large towns. Albanians, who account for 0.36% of the population, settled in the area around Zadar in the 18th century, and after 1945, Albanians also immigrated from Kosovo. In Croatia today, there are also Roma (0.46%), Czechs (0.2%), Macedonians (0.08%), Montenegrins (0.1%), Slovaks (0.1%) and other minorities.

The position of national minorities in Croatia is regulated by the Constitutional Act on the Rights of National Minorities (2002). Among other things, this Act grants national minorities the right to use their own language and script, the right to education in their own languages and script, the right to use their own insignia and emblems, the right to cultural autonomy, the right to practise their own religion, the right to access public media, the right to self-organisation, the right to be represented in representative bodies at national and local levels, and in administrative and judicial bodies, and the right to protection from activities which threaten or may threaten their survival. The same Act also established the Council for National Minorities and the Advisory Council for National Minorities, the members of which represent national minorities in the Croatian Parliament.

In Croatia, as in some other countries, the religious and ethnic compositions of the population match almost completely. Roman Catholics make up 78.97% of the population, and are mostly Croatian by nationality. There are far fewer adherents of other religions. The Orthodox account for 3.32%, mostly Serbs. There are 1.32% Muslims, mostly Bosniacs, and 4.83% members of other Christian denominations. Agnostics, atheists or those who have not declared their religious affiliation amount to 6.43% of the population of Croatia.