The Japanese diaspora and its individual members, known as Nikkei (日系) or as Nikkeijin (日系人), comprise the Japanese emigrants from Japan residing in a country outside Japan. Emigration from Japan was recorded as early as the 15th century to the Philippines, but did not become a mass phenomenon until the Meiji period (1868–1912), when Japanese emigrated to the Philippines and to the Americas. There was significant emigration to the territories of the Empire of Japan during the period of Japanese colonial expansion (1875–1945); however, most of these emigrants repatriated to Japan after the 1945 surrender of Japan ended World War II in Asia.

Japanese people are an East Asian ethnic group native to the Japanese archipelago. Japanese people constitute 97.6% of the population of the country of Japan. Worldwide, approximately 126 million people are of Japanese descent, making them one of the largest ethnic groups. Approximately 122.0 million Japanese people are residents of Japan, and there are approximately 4 million members of the Japanese diaspora, known as Nikkeijin (日系人).