data japan 2024As of 2025, the population of Japan is projected at 123.10 million, compared to 123.75 million in 2025. It is the sixth-most populous country in Asia and ranks 12th in the e populationThe 2025 population density in Japan is 338 people per Km2 (875 people per mi2), calculated on a total land area of 364,555 Km2 (140,755 sq. miles). Largest Cities in Japan City Name