Background: Although Black/African American older adults bear significant inequities in prevalence, incidence, and outcomes of Alzheimer's disease and related dementias, they are profoundly under-included in Alzheimer's Disease research. Community-Engaged Research (e.g., equitable community/science partnerships) is an evidence-based approach for improving engagement of underrepresented populations into Alzheimer's Disease research, but has lacked scalability to the national level. As internet use among older adults from underrepresented populations continues to grow, internet-based research shows promise as a feasible, valid approach to engagement and longitudinal assessment. The Community Engaged Digital Alzheimer's Research (CEDAR) study utilizes a community-engaged research approach to increase the engagement and research participation of Black/African American adults in the Brain Health Registry (BHR) and Alzheimer Disease clinical research., Objectives: To describe the methods and evaluate the feasibility of the CEDAR culturally-informed digital platform within BHR., Design: All Black/African American participants in BHR were invited to enroll in CEDAR and to consider serving on a newly convened Community-Scientific Partnership Board to guide the study. The community board guided the development a culturally-informed cadre of engagement materials and strategies to increase research participation. Engagement strategies included incentives for study task completion, culturally-informed communications (e.g., landing page, emails and social media), resources about brain health, and video and written testimonials by CEDAR participants., Setting: BHR, an Internet-based registry and cohort., Participants: BHR participants self-identifying as Black/African American were invited to enroll. All participants who signed an online informed consent document were enrolled., Measurements: We report the number of participants invited, enrolled, completed tasks, and volunteered to join the community board. We compared the demographics, cognitive profile, and baseline BHR task completion rates between CEDAR participants and all those invited to join the study., Results: Of 3738 invited, 349 (9.34%) enrolled in CEDAR. 134 (37% of CEDAR participants) volunteered to join the community board, of which 19 were selected for the community board. Compared to those invited, the CEDAR cohort had a higher percentage of female participants (84.5%) and a lower percentage of participants who identify as belonging to more than one ethnocultural group (21.8%). Compared to those did not enroll in CEDAR, those enrolled in CEDAR had a higher percentage of participants completing all BHR tasks (22%) and a higher percentage of participants completing at least one cognitive test (76%). Those enrolled in CEDAR also had a higher percentage of participants having an enrolled study partner (18%)., Conclusions: A culturally-informed Community-Engaged Research approach, including a remotely-convened community board, to engagement of Black/African American participants in an online research registry is feasible. This approach can be adapted for use in various clinical studies and other settings. Future studies will evaluate the effectiveness of the engagement strategies., Competing Interests: Danqi Zhu, Dr. Heining Cham, Anna Aaronson, Catherine Conti, Xinyue Deng, Jennefer Sorce, Carole Cypress, Philip Griffin, Derek Flenniken, Monica Camacho, Juliet Fockler, Diana Truran, Dr. R. Scott Mackin, Dr. Carl V. Hill and Dr. Robert Turner have nothing to disclose. Dr. Rivera Mindt reports grants from NIH/NIA Pending # 1R01AG079285-01, during the conduct of the study; grants from U19AG078109-01; R01AG066471; R56AG075744; R13AG071313-01; R01AG065110 - 01A1; SC3GM141996; Genentech Health Equity Innovations 2020 Fund G-89294, outside the submitted work. Dr. Ashford reports grants from NIA during the conduct of the study (F32 AG072730-02). Roxanne Alaniz reports personal fees from eVAL, personal fees from ADNI4, personal fees from SALUD, personal fees from US Pointer, personal fees from Active6, outside the submitted work. Roxanne Alaniz reports personal fees from eVAL, personal fees from ADNI4, personal fees from SALUD, personal fees from US Pointer, personal fees from Active6, outside the submitted work. Dr. Byrd reports grants from Genetech during the conduct of the study. Dr. Weiner reports grants from National Institutes of Health (NIH), grants from Department of Defense (DOD), grants from Patient-Centered Outcomes Research Institute (PCORI), grants from California Department of Public Health (CDPH), grants from University of Michigan, grants from Siemens, grants from Biogen, grants from Hillblom Foundation, grants from Alzheimer’s Association, grants from The State of California, grants from Johnson & Johnson, grants from Kevin and Connie Shanahan, grants from GE, grants from VUmc, grants from Australian Catholic University (HBI- BHR), grants from The Stroke Foundation, grants from Veterans Administration, personal fees from Acumen Pharmaceutical, personal fees from Cerecin, personal fees from Dolby Family Ventures, personal fees from Eli Lilly, personal fees from Merck Sharp & Dohme Corp., personal fees from National Institute on Aging (NIA), personal fees from Nestle/Nestec, personal fees from PCORI/PPRN, personal fees from Roche, personal fees from University of Southern California (USC), personal fees from NervGen, personal fees from Baird Equity Capital, personal fees from BioClinica, personal fees from Cytox, personal fees from Duke University, personal fees from Eisai, personal fees from FUJIFILM-Toyama Chemical (Japan), personal fees from Garfield Weston, personal fees from Genentech, personal fees from Guidepoint Global, personal fees from Indiana University, personal fees from Japanese Organization for Medical Device Development, Inc. (JOMDD), personal fees from Medscape, personal fees from Peerview Internal Medicine, personal fees from Roche, personal fees from T3D Therapeutics, personal fees from WebMD, personal fees from Vida Ventures, personal fees from The Buck Institute for Research on Aging, personal fees from China Association for Alzheimer’s Disease (CAAD), personal fees from Japan Society for Dementia Research, personal fees from Korean Dementia Society, outside the submitted work; and I hold stocks or options with Alzheon Inc., Alzeca, and Anven. Dr. Nosheny reports grants from NIH, grants from Genentech, Inc., grants from California Department of Public Health during the conduct of the study.