Russian Americans are Americans of full or partial Russian ancestry. The term can apply to recent Russian immigrants to the United States, as well as to Russian settlers and their descendants in the 19th-century Russian possessions in what is now Alaska. Russian Americans comprise the largest Eastern European and East Slavic population in the U.S., the second-largest Slavic population after Polish Americans, the nineteenth-largest ancestry group overall, and the eleventh largest from Europe.

In the mid-19th century, Russian immigrants fleeing religious persecution settled in the U.S., including Russian Jews and Spiritual Christians. During the broader wave of European immigration to the U.S. that occurred from 1880 to 1917, a large number of Russians immigrated primarily for economic opportunities; these groups mainly settled in coastal cities, including Brooklyn (New York City) on the East Coast; Los Angeles, San Francisco, Portland, and various cities in Alaska on the West Coast; and Chicago and Cleveland in the Great Lakes region.

After the Russian Revolution and subsequent Russian Civil War from 1917 to 1922, many White émigrés also arrived, especially in New York, Philadelphia, and New England. Emigration from Russia subsequently became very restricted during the Soviet era (1917–1991). However, after the dissolution of the Soviet Union at the end of the Cold War, immigration to the United States increased considerably.

In several major U.S. cities, many Jewish Americans who trace their heritage back to Russia and other Americans of East Slavic origin, such as Belarusian Americans and Rusyn Americans, sometimes identify as Russian Americans. Additionally, certain non-Slavic groups from the post-Soviet space, such as Armenian Americans, Georgian Americans, and Moldovan Americans, have a longstanding historical association with the Russian American community.

According to the Institute of Modern Russia, the Russian American population was estimated at 3.13 million in 2011. The American Community Survey of the U.S. Census shows the slightly over 900,000 Americans age 5 and over spoke Russian at home in 2020.

Many Russian Americans do not speak Russian, having been born in the United States and brought up in English-speaking homes. In 2007, however, Russian was the primary spoken language of 851,174 Americans at home, according to the US census. According to the Davis Center for Russian and Eurasian Studies at Harvard University, 750,000 Russian Americans were ethnic Russians in 1990.

The New York City metropolitan area has historically been the leading metropolitan gateway for Russian immigrants legally admitted into the United States. Brighton Beach continues to be the most important demographic and cultural center for the Russian American experience. However, as Russian Americans have climbed in socioeconomic status, the diaspora from Russia and other former Soviet-bloc states has moved toward more affluent parts of the New York metropolitan area, notably Bergen County, New Jersey. Within Bergen County, the increasing size of the Russian immigrant presence in its hub of Fair Lawn prompted a 2014 April Fool's satire titled, "Putin Moves Against Fair Lawn".

Sometimes, Carpatho-Rusyns and Ukrainians who emigrated from Carpathian Ruthenia in the 19th century and the beginning of the 20th century identify as Russian Americans. More recent émigrés would often refer to this group as the starozhili — "old residents". This group became the pillar of the Russian Orthodox Church in America.^{[citation needed]} Today, most of this group has become assimilated into the local society, with ethnic traditions continuing to survive primarily around the church.