Meta-analytic research has demonstrated that job dissatisfaction levels may be related to lower emotional wellbeing. However, few studies have specifically focused on protective factors that might serve as a buffer in the link between job dissatisfaction and mental health problems in the workplace. This study examined the moderating role of emotion regulation ability (ERA) in the association between job dissatisfaction and mental health problems (i.e., depression, anxiety, and stress symptoms) among 629 professional workers. In a multi-occupational sample, we measured ERA along with indices of job dissatisfaction, depression, anxiety, and stress. The results showed that job dissatisfaction was positively related to depression, anxiety, and stress, but that these relationships were buffered by levels of ERA; that is, higher job dissatisfaction was associated with more mental health problems, but the effect was weaker for those employees with higher ERA. These findings identify emotion-regulation ability as a noteworthy contributor to protection from mental health problems in cases of job dissatisfaction, and highlight the need to consider emotional resources in the workplace when investigating mental health problems relating to chronic job dissatisfaction.