The COVID-19 pandemic spurred significant government investments for hiring public health workers. There are clear opportunities to help build capacities among both current and incoming public health workers, closing well-elucidated skill gaps. To report on the development process, methods used, and outcomes seen from a point-in-time public health workforce capacity-building initiative, Public Health Essentials (PHE) . Capacity-building outcomes evaluation using pre/postintervention measures. The United States. A total of 512 learners working in roles (government or adjacent to) that support public health. PHE, a cohort-based facilitated asynchronous online course comprising 5 units, 18 modules, 54 learning outcomes, and 266 teaching and applied assessment elements designed to build public health strategic skills. Two outputs and 3 outcomes were used to assess and improve progress in achieving our goal of building generalizable and transferrable public health ability and confidence among diverse public health workers: Use of PHE , PHE completion rate , Learner competence , Change in self-assessed ability , and Benefits of PHE. From September 2021 to December 2022, 4 agencies used PHE for fellowship training or employee capacity building. Some 79% (n = 512) of learners completed the training, demonstrating competence in all 54 areas assessed by expert course facilitators. Of those, 79% (n = 321) completed both optional pre- and post-PHE surveys, reporting statistically significant gains in all strategic skill domains assessed (n = 9), regardless of demographics and public health experience. Learners gained new skills and knowledge (92%), developed a better understanding of public health (86%), and broadened their public health skill base (84%). A majority can apply the knowledge and skills gained directly to their work (94%), which benefits their team (92%), and have increased their confidence as public health practitioners (49%). PHE can significantly improve learners' ability across 9 strategic skill areas in as few as 15 weeks, regardless of their demographics, training, or experience.