Asian Americans are Americans of Asian ancestry (including naturalized Americans who are immigrants from specific regions in Asia and descendants of such immigrants). Although this term had historically been used for all the indigenous peoples of the continent of Asia, the usage of the term "Asian" by the United States Census Bureau excludes people with ethnic origins in certain parts of Asia, including West Asia who are now categorized as Middle Eastern Americans; and those from Central Asia who are categorized as Central Asian Americans. The "Asian" census category includes people who indicate their race(s) on the census as "Asian" or reported entries such as "Chinese, Indian, Filipino, Vietnamese, Indonesian, Korean, Japanese, Malaysian, and Other Asian". In 2018, Asian Americans comprised 5.4% of the U.S. population; including multiracial Asian Americans, that percentage increases to 6.5%. In 2019, the estimated number of Asian Americans was 22.9 million.

Chinese, Indian, and Filipino Americans make up the largest share of the Asian American population with 5 million, 4.3 million, and 4 million people respectively. These numbers equal 23%, 20%, and 18% of the total Asian American population, or 1.5% and 1.2% of the total US population.
Although migrants from Asia have been in parts of the contemporary United States since the 17th century (including South Asian slaves), large-scale immigration did not begin until the mid-19th century. Nativist immigration laws during the 1880s–1920s excluded various Asian groups, eventually prohibiting almost all Asian immigration to the continental United States. After immigration laws were reformed during the 1940s–60s, abolishing national origins quotas, Asian immigration increased rapidly. Analyses of the 2010 census have shown that Asian Americans are the fastest-growing racial group in the United States.