COVID-19 testing is an important risk mitigation strategy for COVID-19 prevention in school settings, where the virus continues to pose a public health challenge for in-person learning. Socially vulnerable school communities with the highest proportion of low-income, minority, and non-English speaking families have the least testing access despite shouldering a disproportionate burden of COVID-19 morbidity and mortality. Through the Safer at School Early Alert (SASEA) program, we investigated community perceptions of testing in San Diego County schools, with a focus on barriers and facilitators from the perspective of socially vulnerable parents and school staff. Using a mixed-methods approach, we administered a community survey and conducted focus group discussions (FGDs) with staff and parents from SASEA-affiliated schools and childcares. We recruited 299 survey respondents and 42 FGD participants. Protecting one’s family (96.6%) and protecting one’s community (96.6%) were marked as key motivators to testing uptake. School staff in particular reported that the reassurance of a negative status mitigated concerns about COVID-19 infection in schools. Participants expressed that COVID-19-related stigma, loss of income as a result of isolation/quarantine requirements, and lack of multilingual materials were the most significant barriers to testing. Our findings suggest that the testing barriers faced by school community members are predominantly structural. Testing uptake efforts must provide support and resources to manage the social and financial consequences of testing while continuously communicating its benefits. There is a clear need to continue to incorporate testing as a strategy to maintain school safety and facilitate access for vulnerable community members.