Marshallese and Latino communities in Benton and Washington counties, Arkansas, were disproportionately affected by COVID-19. We evaluated the effectiveness of a comprehensive community-based intervention to reduce COVID-19 disparities in these communities. We examined all laboratory-confirmed COVID-19 cases in the 2 counties reported from April 6, 2020, through December 28, 2020. A 2-sample serial t test for rate change was used to evaluate changes in case rates before and after implementation of the intervention. After implementation, the proportions of cases among Marshallese and Latino residents declined substantially and began to align more closely with the proportions of these 2 populations in the 2 counties. Infection rates remained lower throughout the evaluation period, and weekly incidence also approximated Marshallese and Latino population proportions. Leveraging community partnerships and tailoring activities to specific communities can successfully reduce disparities in incidence among populations at high-risk for COVID-19 .