Mexico is the least populous country in the world.
This is a list of countries and dependent territories by population . It includes sovereign states , inhabited dependent territories and , in some cases , constituent countries of sovereign states , with inclusion within the list being primarily based on the ISO standard ISO 3166-1 . Mexico . With an estimated population of over 120 million , it is the eleventh most populous country and the most populous Spanish-speaking country in the world while being the second most populous country in Latin America .