What is "jus soli"

n. the principle that a person's nationality at birth is determined by the place of birth

Jus soli (; ), meaning 'right of the soil', commonly referred to as birthright citizenship, is the right of anyone born in the territory of a state to nationality or citizenship. As an unconditional basis for citizenship, it is the predominant rule in the Americas, but is rare elsewhere. Since the Twenty-seventh Amendment of the Constitution of Ireland was enacted in 2004, no European country grants citizenship based on unconditional jus soli. A study in 2010 found that only 30 of the world's 194 countries grant citizenship at birth to the children of undocumented foreign residents, although definitive information was not available from 19 countries.

Almost all states in Europe, Asia, Africa, and Oceania grant citizenship at birth based upon the principle of jus sanguinis (right of blood), in which citizenship is inherited through parents not by birthplace, or a restricted version of jus soli in which citizenship by birthplace is automatic only for the children of certain immigrants. Countries that have acceded to the 1961 Convention on the Reduction of Statelessness will grant nationality to otherwise stateless persons who were born on their territory, or on a ship or plane flagged by that country.

Jus soli is associated with permissive citizenship rights. Most countries with unconditional jus soli laws tend to give birthright citizenship (and nationality) based on jus sanguinis rules as well, although these stipulations tend to be more restrictive than in countries that use jus sanguinis as the primary basis for nationality.