Croatian diaspora refers to the Croatian communities that have formed outside Croatia. Estimates on its size are only approximate because of incomplete statistical records and naturalization, but (highest) estimates suggest that the Croatian diaspora numbers between a third and a half of the total number of Croats.
More than four million Croats live in Croatia. The largest community outside Croatia are the Croats of Bosnia and Herzegovina, one of the constitutient nations of that country, amounting to about 750,000.
The Croatian diaspora outside Croatia and Bosnia and Herzegovina amounts to close to a million elsewhere in Europe, and to about 1.5 million overseas. The largest overseas community is reported from the United States and Chile, with about 400,000 members.
In Western Europe, the largest group is found in Germany. The German census reports 228,000 Croats in Germany as of 2006[update], but estimates of the total number of people with direct Croatian ancestry (including naturalized German citizens) range as high as 450,000.
Croats form one of the three constitutient nations in Bosnia and Herzegovina. They are frequently referred to as Bosnian Croats, but since the War in Bosnia and Herzegovina the number of Herzegovinian Croats exceeds the number in Bosnia. The Croats maintain an unofficial capital in Mostar, with the city being home to the largest Croatian population.
There is no precise data regarding Bosnia and Herzegovina's population since the last war. The UNHCR conducted an unofficial census in 1996, but the data has not been recognized. Ethnic cleansing within Bosnia and Herzegovina in the 1990s saw the vast majority of Croats move and take up residence in the Federation of Bosnia and Herzegovina. It is estimated that there are approximately 600,000 Croats in Bosnia and Herzegovina. According to 2000 data from the CIA World Factbook, Bosnia and Herzegovina is ethnically 14.3% Croat.