Historical dataset of population level and growth rate for the Zagreb, Croatia metro area from 1950 to 2025.

In 1800, the population of the region making up present-day Croatia was just over 1.2 million. Croatia's population grew relatively consistently throughout the 19th and early 20th centuries, despite the region suffering around 200,000 fatalities in each of the World Wars. The lack of clearly defined boundaries, mass displacement and general disorganization have made it very difficult for historians to estimate the total number of fatalities suffered by Croatia and by ethnic Croats in this time; additionally, the various ethnic groups within Yugoslavia at the time committed a number of atrocities against one another, which has exacerbated this.

In spite of these events, the population of Croatia would continue to grow steadily until the early 1990s, when it was one of six parts of the Socialist Federative Republic of Yugoslavia. In the wake of communism's demise in Southern Europe in the late 20th century, Croatia claimed its sovereignty in 1991, which set in motion the Croatian War of Independence with Serbia. War was waged for four years, and saw the deaths of more than 20,000 people, while several hundred thousand were displaced. In the quarter century since the war's end, Croatia has emerged as a high-income, developing country, with a booming tourism and hospitality industry. However the population has continued to drop as a result of declining birth rates, and large-scale economic migration (particularly influenced by the financial crisis of 2008 and Croatia's accession to the European Union in 2013).

This statistic shows the biggest cities in Croatia in 2021. In 2021, approximately **** million people lived in Zagreb, making it the biggest city in Croatia .