More than 1.5 billion people, about 38 percent of the population of Asia or 22 percent of all the people in the world, live in geographic East Asia. This is about twice the population that Europe has. The region is one of the world's most populated places, with a population density of 131 inhabitants per square kilometre (340 /sq mi), being about three times the world average of 45 /km2 (120 /sq mi). Using the UN subregion definitions, it ranks second in population only to Southern Asia.

Historically, many societies in East Asia have been part of the Chinese cultural sphere, and East Asian vocabulary and scripts are often derived from Classical Chinese and Chinese script. Sometimes Northeast Asia is used to denote Japan, North Korea, and South Korea.

Major religions include Buddhism (mostly Mahayana), Confucianism or Neo-Confucianism, Taoism, Chinese folk religion in China, Shinto in Japan, Shamanism in Korea, Mongolia and other indigenous populations of northern East Asia, and more recently Christianity in South Korea. The Chinese Calendar is the root from which many other East Asian calendars are derived.