How Many Illegal Aliens Are in the United States? 2025 Update
March 7, 2025
A FAIR Research Report | March 2025
FINDINGS
As of March 2025, FAIR estimates that approximately 18.6 million illegal aliens reside in the United States. This is 11 percent higher than our June 2023 illegal alien population estimate of 16.8 million.[1]
Since our December 2020 estimate, the illegal alien population in the United States has grown by 4.1 million, or 28.2 percent, reflecting an unprecedented wave of illegal immigration during the Biden administration. The surge in illegal immigration was so large that the U.S. Census Bureau announced just three months ago it has changed its methodology for estimating the foreign-born population to account for it.
As of 2025, American population growth comes almost entirely from unsustainably high levels of immigration, both legal and illegal.[2]
FIGURE 1: ILLEGAL ALIEN POPULATION IN U.S. SINCE 2013 (MILLIONS). DATA SOURCE: FAIR ESTIMATES. CHART BY FAIR
Illegal Alien Population in U.S. Since 2013 (Millions). Data Source: FAIR Estimates. Chart by FAIR
WHO IS AN ILLEGAL ALIEN?
https://www.fairus.org/issue/how-many-illegal-aliens-are-united-states-2025-update
