Objectives: To determine whether culturally adapted dementia prevention animations increased dementia prevention knowledge in ethnically diverse communities. Methods: A before-and after survey conducted online and in-person between 1 February and 5 June 2022. Participants viewed the animation in Arabic, Hindi, Tamil, Cantonese, Mandarin, Greek, Italian, Spanish, Vietnamese or English. Dementia knowledge was measured using two subscales from the dementia risk reduction knowledge instrument (KoDeRR), measuring knowledge of dementia risk factor mitigation strategies and appraisal of dementia risk factors (misconceptions). Results: Among the 318 respondents there was a significant increase in dementia knowledge in most languages after viewing the animation (ps < 05; except for English). Mean performance on knowledge of dementia risk factor mitigation strategies significantly increased after viewing the animation (p <.001), with a clinically meaningful effect (mean change = 3.63). Appraisal of dementia risk factor misconceptions significantly increased in the Spanish group (mean change = 1.29, p <.001), but significantly decreased in the English group (mean change = -1.09, p <.001). Conclusions: Viewing the animation in a language other than English was associated with an increase in KoDeRR scores for both the recognition of mitigation strategies and identification of misconceptions subscales. Clinical implications: Codesigned, culturally adapted in-language dementia prevention animations improve dementia prevention awareness in ethnically diverse communities.