Allochtoon (plural: allochtonen) is a Dutch word (derived from Greek ἀλλος (allos), other, and χθον (chthon) earth/land), literally meaning "originating from another country". It is the opposite of the word autochtoon (in English, "autochthonous" or "autochthone"; derived from Greek αυτο (auto), self) literally meaning "originating from this country".
In the Netherlands (and Flanders), the term "allochtoon" is widely used to refer to immigrants and their descendants. Officially the term allochtoon is much more specific and refers to anyone of whom one or both of his/her parents was not born in the Netherlands. Hence, third generation immigrants, are no longer considered allochtoon (if both their parents were born in the Netherlands), though this does not automatically make them ethnically Dutch. The corresponding antonym autochtoon is less widely used, but it roughly corresponds to ethnic Dutch. Among a number of immigrant groups living in the Netherlands, a "Dutch" person (though they are themselves Dutch citizens) usually refers to the ethnic Dutch.
In 1950, Dutch descent, Dutch nationality, and Dutch citizenship were in practice identical. The Netherlands was largely a mono-ethnic society with some colonial influences (if the Frisians are considered part of the Dutch ethnic group). In 1950, most Dutch were either Catholic or Protestant, with some atheists. Decolonisation and immigration from the 1960s on, altered the ethnic and religious composition of the country - there are now about one million Muslims. This development has made the 'ethnicity' and national identity of the Dutch a political issue.
Dutch nationality law is based primarily on the principle of Jus sanguinis ("Right of blood"). In other words, citizenship is conferred primarily by birth to a Dutch parent, irrespective of place of birth.
A first distinction is made between first- and second-generation newcomers.
Note that someone who is born abroad, but both of whose parents were born in the Netherlands, is an autochtoon.
A further distinction is made between 'western' and 'non-western' allochtonen. A non-western allochtoon is someone whose 'country of origin' is or lies in Turkey, Africa, Latin America and Asia, with the exception of Indonesia (or the former Dutch East Indies) and Japan.
This last distinction was made because the official definition of 'allochtoon' deviates from the common use in popular speech, where people refer to someone as allochtoon only when that person is an immigrant or an asylum seeker who is clearly distinct in appearance (race or clothing) or behaviour from the traditional Dutchman. However, in the official sense, the largest group of "allochtonen" are of German ancestry. The groups that people usually think of when they hear the word 'allochtoon' are those of Turkish, Moroccan and Surinamese ancestry. As of 2006, these groups comprise roughly 350,000 people each, together constituting just over 6% of the population.
So a new term was introduced that lies closer to that meaning, 'niet-westers allochtoon', which excludes 'allochtonen' from Europe, Japan (a westernised country) and Indonesia (a former colony), but not those from the Netherlands Antilles and Surinam, which seems odd because the Antilles are still part of the kingdom of the Netherlands (the inhabitants have a Dutch passport) and those from Surinam immigrated when that country was still part of the Netherlands. Hoewever, many Indonesian allochtones are white (former colonists), while most Surinam and Antillian allochtones are black (former slaves), so this definition coincides better with people's conception of the word.