A foreign worker or guest worker is a human who works in a country other than the one of which he or she is a citizen. Some foreign workers are using a guest worker program in a country with more preferred job prospects than their home country. Guest workers are often either sent or invited to work outside their home country, or have acquired a job before they left their home country, whereas migrant workers often leave their home country without having a specific job at hand.
Tens of millions of people around the world live their lives as foreign workers. An estimated 14 million foreign workers live in the United States, which draws most of its immigrants from Mexico, including 4 or 5 million undocumented workers. It is estimated that around 5 million foreign workers live in Northwestern Europe, half a million in Japan, and around 5 million in Saudi Arabia. A comparable number of dependents are accompanying international workers.
Foreign nationals are accepted into Canada on a temporary basis if they have a student visa, are seeking asylum, or under special permits. The largest category however is called the Temporary Foreign Worker Program (TFWP), under which workers are brought to Canada by their employers for specific jobs. In 2006, there were a total of 265,000 foreign workers in Canada. Amongst those of working age, there was a 118% increase from 1996. By 2008, the intake of non-permanent immigrants (399,523, the majority of whom are TFWs), had overtaken the intake of permanent immigrants (247,243).
Green card workers are individuals who have requested and received legal permanent residence in the United States from the government and who intend to work in the United States on a permanent basis.
In Nazi Germany, from 1940–42, Organization Todt began its reliance on guest workers, military internees, Zivilarbeiter (civilian workers), Ostarbeiter (Eastern workers) and Hilfswillige ("volunteer") POW workers.