Executive safety leadership is essential to prevent accidents in the workplace. However, will safety be secured by emphasizing only executive safety leadership to workers? In this study, the impact of executive safety leadership on the workplace hazard level was analyzed by adding the supervisor's safety role as a mediating variable. This paper shows that executive safety leadership has no direct effect on workplace hazard levels. However, executive safety leadership was found to have a significant impact on the supervisor safety role, and the supervisor safety role was found to lower the hazard levels in the workplace. In summary, executive safety leadership was found to reduce the hazard levels in the workplace through the full mediating effect of the supervisor safety role. Based on these research results, this study seeks to present the following recommendations to the government and management: The government should ensure that a workplace safety and health system is established by strengthening the effects of other mediating factors, such as strengthening the role of supervisors who are actually responsible for workplace safety and health. Executives must grant supervisors actual authority and responsibility to properly perform their safety roles and establish personnel and performance evaluation systems.