Pain invalidation (e.g., having pain discounted) is a risk factor for depression among people with chronic pain, but the mechanisms remain unclear. Shame is a common, yet understudied, aspect of the pain experience. This study investigated whether pain-related shame helps explain the relationship between pain discounting and heightened depressive symptoms. The secondary aim was to examine whether social support can protect against the harmful effects of discounting. Patients with chronic pain (N = 305) were recruited from outpatient pain clinics. Participants completed an online cross-sectional survey and data were analyzed using moderated mediation analysis. Greater discounting was associated with greater depressive symptoms, and pain-related shame significantly mediated this relationship. Perceived social support attenuated the relationship between discounting and depressive symptoms. Greater attention towards pain-related shame as a treatment target is needed. Individual- and system-level interventions are required to address pain invalidation and bolster support for this population.