Individuals affected by chronic lower-back pain and obesity have an increased risk of long-lasting disability. In this study, we aimed to explore the contribution of kinesiophobia and pain catastrophizing in explaining pain intensity and pain-related disability in chronic lower-back pain associated to obesity. A cross-sectional study on 106 participants with obesity and chronic lower-back pain was performed. We assessed pain intensity, pain disability, pain catastrophizing, and kinesiophobia levels through self-reporting questionnaire. Hierarchical regressions were performed to assess the role of pain catastrophizing and kinesiophobia on pain intensity and pain disability. According to the results, kinesiophobia, but not pain catastrophing, significantly explained both pain intensity and pain-related disability. Kinesiophobia might play a significant role in enhancing pain-related disability and the pain intensity in individuals with chronic lower-back pain and obesity. We encourage future studies in which beliefs and cognition towards pain might be a therapeutic target in interdisciplinary pain management interventions.