American ancestry refers to people in the United States who self-identify their ancestral origin or descent as "American", rather than the more common officially recognized racial and ethnic groups that make up the bulk of the American people. The majority of these respondents are visibly White Americans, who are far removed from and no longer self-identify with their original ethnic ancestral origins. The latter response is attributed to a multitude of generational distance from ancestral lineages, and these tend be Anglo-Americans of English, Scotch-Irish, Welsh, Scottish or other British ancestries, as demographers have observed that those ancestries tend to be recently undercounted in U.S. Census Bureau American Community Survey ancestry self-reporting estimates.

Americans are the citizens and nationals of the United States. The United States is home to people of many racial and ethnic origins; consequently, American law does not equate nationality with race or ethnicity, but with citizenship and an oath of permanent allegiance.