​Summary: This study aims to quantify COVID-19 vulnerabilities for California residents by their legal immigration status and place of residence. Using restricted data from adult respondents in the 2015–2020 California Health Interview Survey (CHIS), authors measure the Relative Social Vulnerability Indices for COVID-19 by legal immigration status and census region across six domains: socioeconomic vulnerability; demography and disability; minority status and language barriers; high housing density; epidemiological risk; and access to care.

Findings: Undocumented immigrants living in Southern California’s urban areas (Los Angeles, Orange, San Diego-Imperial) have exceptionally high vulnerabilities due to low socioeconomic status, high language barriers, high housing density and low access to care. San Joaquin Valley is home to vulnerable immigrant groups and a U.S.-born population with the highest demographic and epidemiological risk for severe COVID-19. Interventions to mitigate public health crises must explicitly consider immigrants’ dual disadvantage from social vulnerability and exclusionary state and federal safety-net policies.