Background: People with intellectual disabilities are at risk of experiencing stigma and require the skills and confidence to deal with stigma in their daily lives. Method: Development and piloting of a 5-session manualised psychosocial group intervention designed to increase the capacity of people with intellectual disabilities aged 16+ to manage and resist stigma. Ten pre-existing groups (N = 67) in third sector and education settings participated. Interviews with participants (n = 26), facilitators (n = 9) and significant others (n = 7) 2-4 months after the intervention assessed perceived impact. Results: Perceived benefits of the intervention for participants included increased understanding, improved connections with others, drive for advocacy, increased activity and self-efficacy, and opportunity to process difficult events and emotions. Differential impact depending on individuals' pre-existing self-advocacy skills was noted. Conclusions: This early-stage study indicates that further evaluation is merited to examine feasibility and outcomes of the STORM intervention.