Background: The coronavirus disease 2019 (COVID-19) pandemic has caused health problems and distress among healthcare workers (HCWs), so supportive measures to promote their health and relieve distress are needed. Materials and Methods: We conducted two rounds of Delphi surveys with 20 COVID-19-related frontline healthcare professionals and public officials. The surveys evaluated means of supporting HCWs’ health by improving health care systems and working environments in terms of effectiveness and urgency. The validity of the measures was assessed by calculating the content validity ratio. Results: The top-priority measures to support HCWs were “secure isolation units capable of treating severe cases” in the facility infrastructure category, “secure nursing staff dedicated for patients in the intensive care units” in the personnel infrastructure category, “improve communication between central office and frontline field” in the cooperation system category, “support personal protective equipment and infection control supplies” in the aid supplies category, and “realization of hazard pay” in the physical/mental health and compensation category. Conclusion There was consensus among the experts on the validity and priorities of policies in the facility, personnel, cooperation, supplies, and compensation categories regarding measures to promote COVID-19 related HCWs’ health.