Burnout in health care workers (HCWs) has serious ramifications for individual well-being, patients, organizations, and health systems. Global evidence demonstrates the COVID-19 pandemic has amplified the risk of burnout. Scalable interventions to address burnout are critical to protect HCW well-being. Underpinned by the Conservation of Resources theory, this study examines the impacts of a statewide improvement initiative (the Initiative), using the Institute for Healthcare Improvement Joy in Work (JiW) Framework, to reduce burnout and increase joy at work across participating health care organizations in Victoria, Australia. An impact evaluation was undertaken utilizing a mixed-methods design. Quantitative outcomes included burnout and joy at work measured using an adapted Mini Z tool. In-depth interviews with implementation teams sought insights into the effectiveness of interventions. Overall, 20 teams from 17 organizations across diverse health care settings and geographical locations participated. At a statewide level, outcomes in burnout and joy at work were inconclusive due to limited data. However, five out of eight teams reporting sufficient data achieved measurable improvements in one or more outcomes. Qualitative data revealed the Initiative increased workplace resources and supports such as providing "permission" for HCWs to prioritize well-being at work, improved communications between management and HCWs, and increased HCWs' teamwork and camaraderie, resulting in safer and more positive workplaces. The JiW Framework, implemented across diverse settings, provided organizations with a structured process to develop multifaceted improvements that resulted in enhanced resources that appeared to improve HCW well-being. Compared to individual well-being support, this approach offers organization-level change and scalability potential.