On 4 October 1830, Belgium declared its independence. The Netherlands recognized the situation on 19 April 1839. But the National Holiday is 21 July, as Prince Leopold of Saxe-Coburg and Gotha took the constitutional oath to become King of the Belgians.
In the days before 21 July 2026; Statbel looked ahead to the kingdom’s bicentenary in 2030, nearly two centuries of official population statistics reveal how dramatically the country’s demographic landscape has changed. According to new figures published by Statbel, Belgium’s population has grown from just under 3.8 million people at the time of independence to almost 12 million at the start of 2026.
Since Belgium became independent in 1830, the country’s population has expanded almost continuously. On 1 January 2026, Belgium was home to 11,867,634 inhabitants, more than three times the 3,786,556 people recorded during the early years of the new nation. Statbel, Belgium’s national statistical office, has been responsible for producing the country’s official population figures since 1831, although the institution has operated under several names over the years, including the Central Commission for Statistics, the National Institute for Statistics (NIS) and the General Directorate for Statistics.
Wars and crises left a lasting demographic mark
The historical data show that Belgium’s population growth has not always followed a steady path. World War I had a particularly visible impact, with the population declining slightly between 1910 and 1920, from 7.42 million to 7.40 million inhabitants. Heavy wartime casualties and a sharp decline in births temporarily reversed decades of growth.
Following World War II, population growth accelerated once again. The post-war baby boom, combined with economic recovery, contributed to a sustained increase in the number of inhabitants throughout the second half of the twentieth century.
More recently, global events have also left their mark. During the COVID-19 pandemic in 2020, Belgium’s population growth slowed as excess mortality coincided with a sharp fall in international migration.
By contrast, 2022 saw one of the strongest annual population increases in decades. The Russian invasion of Ukraine triggered a significant rise in international migration to Belgium, resulting in exceptionally strong population growth that year.
Migration now outweighs natural population growth
The figures also illustrate how the drivers of population growth have changed over time. Throughout most of the twentieth century, Belgium’s population expanded through a combination of natural growth – with births exceeding deaths – and positive international migration, meaning more people arrived in the country than left it.
Since the beginning of the twenty-first century, however, international migration has become the dominant factor behind population growth. Belgium now regularly records more deaths than births, creating a negative natural balance. That demographic deficit is offset by positive net migration, which has become the country’s principal source of population growth.
Nearly two centuries of demographic change
According to Statbel, almost 200 years of population statistics provide a unique insight into how Belgium has evolved since independence. The figures demonstrate that wars, economic developments, public health crises and international migration have all shaped the country’s demographic history.
With Belgium set to celebrate its 200th anniversary in 2030, the long-term statistics also illustrate how profoundly the nation has changed. From a country of fewer than four million inhabitants in the nineteenth century, Belgium has developed into a nation of almost 12 million people, with international migration now playing a greater role in shaping its future than ever before.
