While it is known that fibromyalgia patients often suffer from depression and stress symptoms, there is inconclusive evidence as to why these symptoms occur. The aim of this study is to examine the role of emotion regulation in mental health symptoms among treatment-seeking individuals with fibromyalgia. Ninety-three (93) participants (mean age = 47.25, SD = 12.4) were recruited from one of Israel’s largest community healthcare providers. They were administered self-report questionnaires assessing fibromyalgia (FIQR), perceived stress (PSS), major depression (PHQ-9), and difficulties in emotion regulation (DERS). Associations were found between measures of fibromyalgia symptoms, psychological distress, and emotion regulation. Several sub-indices of emotion regulation showed significant correlations with psychological distress, with non-acceptance of emotional responses showing the strongest associations. Moreover, non-acceptance of emotion responses mediated the association between fibromyalgia symptoms and psychological distress. Our findings show that the connection between fibromyalgia symptoms and psychological distress is partially explained by difficulties in emotion regulation. Moreover, we show that specific emotion regulation strategies play a differential role in fibromyalgia patients’ distress, thereby highlighting the importance of identifying unique psychotherapeutic targets. Specifically, regulating emotions through acceptance of emotional responses seems to be particularly important for fibromyalgia patients, as they cope with stigma and a lack of validation.