Mexico is a Third World country, although many people misunderstand the term "Third World," according to One World Nations Online. While the term has come to represent poor or developing countries, originally it designated a country not directly aligned with the West or the Soviet Union after World War II.
During the Cold War following World War II, the world was split into two spheres of influence. The First World was the United States and its NATO allies in Europe and elsewhere. The Second World represented the Soviet bloc, its allies and satellite states, such as Cuba. Any country that didn't fit into either of those spheres was considered Third World.