Deaf individuals often experience systematic marginalization, compounded by the near absence of mental health-related vocabulary in Bangla Sign Language. Through two exploratory workshops and a participatory co-design process—including an adapted three-phase Delphi study and three collaborative workshops—this initiative led to the development of the first digitally delivered Bangla Mental Health Sign Language Bank. Key themes emerging from the qualitative data include widespread social stigma, emotional isolation, denial of healthcare, and limited capacity to articulate psychological distress, with positive family support emerging as a critical protective factor. The presentation underscores the importance of community-led solutions, linguistically inclusive tools, and culturally grounded digital interventions. Key takeaways include: (1) the urgent need to expand sign language resources to encompass mental health terminology; (2) the value of participatory methods in co-developing accessible mental health tools; and (3) the potential of digital innovations to reduce mental health disparities in underserved populations. The Bangla Mental Health Sign Language Bank offers a scalable model for improving mental health communication and awareness among deaf communities in Bangladesh and similarly underrepresented contexts.