Background and objective: Today, the roles of leaders and employees have become crucial for corporate performance, with leaders having a significant effect on employees. This study aimed to analyze leaders’ effect on employees’ job satisfaction. It also aimed to analyze the effect of employees’ depression and job autonomy on the relationship between leaders’ roles and employees’ job satisfaction by employment type. Materials and methods: In total, 24,327 cases from the 5th Korean Working Conditions Survey were analyzed; the established hypotheses were tested using partial least squares structural equation modeling. Results: In both regular and non-regular employees, the leader’s role had a positive effect on job satisfaction. Job autonomy and depression had a mediating effect. The effect of the leader’s role on job autonomy was greater in regular employees compared to non-regular employees; however, the effect of the leader’s role on depression was greater in non-regular employees. Conclusions: For non-regular employees, the expansion of job autonomy is limited due to the nature of their work. This implies that the greater focus of leaders should be on reducing depression resulting in increasing employees’ job satisfaction. For regular employees, the leaders’ focus should be on expanding job autonomy, which will be effective in increasing employees’ job satisfaction.