Massachusetts has one of the highest cumulative incidence rates of coronavirus disease 2019 (COVID-19) cases in the US. Understanding which specific demographic, economic, and occupational factors have contributed to disparities in COVID-19 incidence rates across the state is critical to informing public health strategies. We performed a cross-sectional study of 351 Massachusetts cities and towns from January 1 to May 6, 2020, and found that a 10-percentage-point increase in the Black non-Latino population was associated with an increase of 312.3 COVID-19 cases per 100,000 population, whereas a 10-percentage-point increase in the Latino population was associated with an increase of 258.2 cases per 100,000. Independent predictors of higher COVID-19 rates included the proportion of foreign-born noncitizens living in a community, mean household size, and share of food service workers. After adjustment for these variables, the association between the Latino population and COVID-19 rates was attenuated. In contrast, the association between the Black population and COVID-19 rates persisted but may be explained by other systemic inequities. Public health and policy efforts that improve care for foreign-born noncitizens, address crowded housing, and protect food service workers may help mitigate the spread of COVID-19 among minority communities.