Community engagement managers are increasingly seen as vital and irreplaceable elements for the smooth functioning of healthy online communities. Though it is a new field, community engagement has matured quickly, with a growing body of common methods and best practices. Individuals playing this role in scientific contexts, however, are often isolated from this community of practice, and left to trial and error to figure out how to be most effective. This grant supports a Community Engagement Fellowship program at the American Association for the Advancement of Science (AAAS) for a network of community engagement managers that will connect several scientific fields. The Fellows will be based in a combination of AAAS-affiliated scholarly societies and large multidisciplinary collaborations, which will build capacity in scientific organizations. In addition, fellows will be brought together for annual training boot camps and monthly professional development webinars, allowing them to share ideas, common challenges, and best practices. Grant funds support approximately half of the planned 18 fellows of the initial cohort, with additional funds provided to offset the costs of outreach, fellow selection, and program administration.