Assyrian Americans (Syriac: ܣܘܼܖ̈ܵܝܹܐ ܐܲܡܪ̈ܝܼܟܵܝܹܐ) are individuals of ethnic Assyrian ancestry born or residing within the United States. Assyrians are an ethnic group native to Mesopotamia in West Asia who descend from their ancient counterparts, directly originating from the ancient indigenous Mesopotamians of Akkad and Sumer who first developed the independent civilization in northern Mesopotamia that would become Assyria in 2600 BC. Modern Assyrians often culturally self-identify as Syriacs, Chaldeans, or Arameans for religious and tribal identification. The first significant wave of Assyrian immigration to the United States was due to the Sayfo genocide in the Assyrian homeland in 1914–1924.

The largest Assyrian diaspora in the United States is located in Metro Detroit, with a figure of 150,000. High concentrations are also located in Phoenix, San Jose, Modesto, San Diego, Los Angeles, Turlock, and Chicago among others.

In the 2020 U.S. census a total of 119,402 individuals identified as Assyrian, Chaldean or Syriac in the United States with full or partial ancestry.

As of 2022^[update] U.S. Census Bureau estimates, there are 94,532 people in the United States declaring Assyrian/Chaldean/Syriac ancestry (with a margin of error ±7,255).

Assyrian immigration to the United States began in the late 19th century, with a notable presence developing in New England. Syriac Orthodox Assyrians from Harput were among the early settlers, establishing a community in Worcester, Massachusetts. Many later relocated to the Boston area. This community maintained close ties with other Syriac Orthodox Assyrians, particularly those from Mardin, who settled in Central Falls, Rhode Island, and from Diyarbakır, who established communities in New Jersey. The community in New Jersey founded several civic organizations outside the church, including the Assyrian Orphanage and School Association of America.

The early Syriac Orthodox communities also developed relationships with other early Assyrian groups, such as Protestants and members of the Church of the East, who then primarily emigrated from Urmia (in northwestern Iran) and settled in New Britain, Connecticut.

Following the turn of the century, Assyrian immigration to America mostly came to a halt due to the Immigration Act of 1924, which effectively cut off any legal immigration to the United States for Assyrians and other non-Western European groups. The second large wave of immigration occurred in the 1960s and 1970s, mainly from northern Iraq due to conflicts and persecution by the Ba'athist government of Iraq. Others arrived from Iran following the Iranian Revolution. Many Assyrians arrived during this period and took advantage of the ongoing White flight in Detroit.

As a result of the situation, Assyrians gained a monopoly over grocery stores and other small businesses, and in many cases used their finances and newfound wealth to benefit the Assyrian community there and take in Assyrian refugees from Iraq. More Assyrians arrived throughout the 1980s and 1990s for similar reasons, with newer residents moving out of Detroit into suburbs such as Royal Oak and Sterling Heights due to the crack epidemic in Detroit, while others began to move to San Diego, establishing a new Assyrian community there.