Indian Americans are Americans whose ancestry originates wholly or partly from India. The terms Asian Indian and East Indian are used to avoid confusion with Native Americans in the United States, who are also referred to as "Indians" or "American Indians". With a population of more than 5.4 million, Indian Americans make up approximately 1.6% of the U.S. population and are the largest group of South Asian Americans, the largest Asian-alone group, and the second-largest group of Asian Americans after Chinese Americans.

The Indian American population started increasing, especially after the 1980s, with U.S. migration policies that attracted highly skilled and educated Indian immigrants. Indian Americans have the highest median household income and the second highest per capita income (after Taiwanese Americans) among other ethnic groups working in the United States. "Indian" does not refer to a single ethnic group, but is used as an umbrella term for the various ethnic groups in India.

In the Americas, the term "Indians" had historically been used to describe indigenous people since European colonization in the 15th century. Qualifying terms such as "American Indian" and "East Indian" were and still are commonly used in order to avoid ambiguity. The U.S. government has since coined the term "Native American" in reference to the indigenous people of the United States, but terms such as "American Indian" remain among indigenous as well as non-indigenous populations. Since the 1980s, Indian Americans have been categorized as "Asian Indian" (within the broader subgroup of Asian American) by the U.S. Census Bureau.

While "East Indian" remains in use, the terms "Indian" and "South Asian" are often chosen instead for academic and governmental purposes. Indian Americans are included in the census grouping of South Asian Americans, which includes Bangladeshi Americans, Bhutanese Americans, Indo-Caribbean Americans, Maldivian Americans, Nepalese Americans, Pakistani Americans, and Sri Lankan Americans.

Beginning in the 17th century, members of the East India Company would bring Indian servants to the American colonies. There were also some East Indian slaves in the United States during the American colonial era. In particular, court records from the 1700s indicate a number of "East Indians" were held as slaves in Maryland and Delaware. Upon freedom, they are said to have blended into the free African American population, considered "mulattoes".

In 1850, the federal census of St. Johns County, Florida, listed a 40-year-old draftsman named John Dick, whose birthplace was listed as "Hindostan", living in city of St. Augustine. His race is listed as white, suggesting he was of British descent.

By 1900, there were more than 2,000 Indian Sikhs living in the United States, primarily in California. At least one scholar has set the level lower, finding a total of 716 Indian immigrants to the U.S. between 1820 and 1900. Emigration from India was driven by difficulties facing Indian farmers, including the challenges posed by the colonial land tenure system for small landowners, and by drought and food shortages, which worsened in the 1890s. At the same time, Canadian steamship companies, acting on behalf of Pacific coast employers, recruited Sikh farmers with economic opportunities in British Columbia.

The presence of Indians in the U.S. also helped develop interest in Eastern religions in the U.S. and would result in its influence on American philosophies such as transcendentalism. Swami Vivekananda arriving in Chicago at the World's Fair in 1893 led to the establishment of the Vedanta Society.