INTRODUCTION: Low health literacy about Alzheimer's disease and related disorders (ADRD) may limit help-seeking, early detection, and enrollment in clinical trials, particularly in minoritized communities. We created the Dementia Literacy Assessment (DeLA) to improve ADRD health literacy. METHODS: The DeLA, a storytelling method that included culturally adaptable vignettes embedded with important factoids about ADRD, was administered to 213 participants from urban and rural regions of Palm Beach and Broward County in Florida and 193 participants in American Samoa. RESULTS: The DeLA increased dementia health literacy and performed well across different participant characteristics (age, sex, education, geographic locale, race, ethnicity, and cognitive performance). Gains in ADRD health literacy were associated with older age, more education, better socioeconomic status, greater resilience, and better cognitive performance. DISCUSSION: Increasing ADRD health literacy could increase health-seeking behaviors in diverse populations for treatment, enrich recruitment into clinical trials, and may help reduce disparities in health outcomes. HIGHLIGHTS: Low health literacy about Alzheimer's disease and related disorders (ADRD) may limit help-seeking, early detection, and enrollment in clinical trials, particularly in minoritized communities.The Dementia Literacy Assessment (DeLA), a storytelling method that included culturally adaptable vignettes embedded with important factoids about ADRD, was administered to 406 participants from urban and rural regions of Palm Beach and Broward County in Florida and American Samoa (11.8% White, 39.8% Black or African American, and 48.4% Pacific Islander [predominantly Samoan] individuals).The DeLA increased dementia health literacy and performed well across different participant characteristics (age, sex, education, geographic locale, race, and cognitive performance).Gains in ADRD health literacy were associated with older age, more education, better socioeconomic status, greater resilience, and better cognitive performance.Increasing ADRD health literacy could increase health-seeking behaviors in diverse populations for treatment, enrich recruitment into clinical trials, and help reduce disparities in health outcomes.