Background Health experts believe that frequent COVID-19 testing is one of the most important practices for stopping the spread of the COVID-19 virus. Demographic and social factors might play a role in whether a person gets tested for COVID. This present study aimed to investigate (1) the demographic and social factors affecting a person’s likelihood of getting tested for COVID-19, and (2) the demographic and social factors related to a positive serology test (i.e., indicating likely past infection). Methods Data were extracted from a survey conducted in Delaware’s underserved communities. Participants were asked to complete a questionnaire about their COVID-19 testing history, and nurses at the study site collected a serology sample from each participant. Results Our results indicated that Black or Hispanic individuals living in underserved communities had greater odds of having been tested previously for COVID compared to being non-Hispanic White. In addition, our study found that being female, educated, feeling safe in one’s neighborhood, being vaccinated against COVID, and being an essential worker increased one’s odds of having been previously tested for COVID-19. Regarding the results of the COVID-19 antibody serology tests, our findings revealed that Hispanic respondents were more likely to have a positive serology test compared to non-Hispanic White respondents, indicating that the Hispanic individuals were more likely to contract the virus. Educated individuals were less likely to have a positive serology test compared to the less-educated. Those who expressed hesitancy about getting vaccinated for COVID-19 and identified themselves as essential workers were more likely to have a positive serology test and to have previously contracted the virus. Conclusions Identifying key factors associated with COVID-19 testing may help establish novel strategies to increase testing rates among vulnerable population. Public health and policy implications are discussed in the article.