Individuals with ADHD report diminished emotion regulation capacities and adversity in childhood detrimentally affects emotion regulation development; however, how positive childhood experiences (PCEs) and whether and how social support are related to PCEs and emotion regulation for those with ADHD is unknown. Objective: To identify direct and indirect associations between PCEs and social support to emotion regulation outcomes in adults with ADHD. Method: Adults with ADHD (n = 81) reported PCEs, current social support, and emotion regulation. Conditional effects modeling examined the direct and indirect relationships between PCEs and emotion dysregulation through social support. Results: Higher PCEs were indirectly related to improved emotion regulation through increased social support generally ([beta] = -0.70, 95% CI [-1.32, -0.17], and specifically through belonging ([beta] = -0.43, 95% CI [ -0.87, -0.05], self-esteem ([beta] = -0.61, 95% CI [-1.08, -0.27], and tangible social support ([beta] = -0.50, 95% CI [-1.07, -0.02]. Conclusions: PCEs may protect emotion regulation in adults with ADHD through social support, possibly through facilitating social connections, increasing access to social support, and sustaining emotion regulation strategies