BACKGROUND: The immigration enforcement system has significant effects on the health of immigrants, their families, and society. Exposure to the immigration enforcement system is linked to adverse mental health outcomes, which may have been exacerbated by sustained immigration enforcement activities during the COVID-19 pandemic. OBJECTIVES: This study was conducted to investigate the association between exposure to immigration enforcement and the mental health of undocumented young adults in California during the COVID-19 pandemic. METHODS: Data are from the COVID-19 BRAVE (Building Community Raising All Immigrant Voices for Health Equity) Study, a community-engaged cross-sectional survey of the impacts of the COVID-19 pandemic on undocumented immigrants in California. A total of 366 undocumented immigrants between 18 and 39 years of age completed the online survey, which was conducted between September 2020 and February 2021. Multivariable logistic regression models were fit to examine the association between immigration enforcement exposure and depression. RESULTS: Almost all participants (91.4%) disclosed exposure to the immigration enforcement system, with most reporting an average of 3.52 (SD=2.06) experiences. Multivariate analyses revealed that an increase in the immigration enforcement exposure score was significantly associated with higher odds of depression (adjusted odds ratio [aOR]=1.24; 95% confidence interval [CI]: 1.10, 1.40), and women were 92% more likely to report depression than were men (aOR=1.92; 95% CI: 1.12, 3.31). Those who reported deportation fears were significantly more likely to be depressed (aOR=1.24; 95% CI: 1.10, 1.40). CONCLUSIONS: Researchers should consider the mental health implications of a punitive immigration enforcement system, and policymakers should examine the impacts of immigration policies on local communities.