Introduction: Deaf communities experience barriers to mental health care related to communication, language, and cultural differences. However, opportunities for bidirectional learning between Deaf community members and mental health professionals remain limited. This program aimed to strengthen mental health knowledge among Deaf leaders and improve mental health professionals’ understanding of Deaf culture and communication. Method: A two-day collaborative training was conducted in Bandung involving 19 Deaf community leaders and 12 hearing mental health professionals. Activities included group-specific seminars, interactive discussions, Bahasa Isyarat Indonesia (Bisindo) demonstrations, and a joint learning session. Changes in knowledge were evaluated using customized pre- and post-tests, while participant experiences and reflections were analyzed qualitatively. The Self-Reporting Questionnaire (SRQ-20) was administered to Deaf participants as a screening instrument to describe their initial mental health context. Results: Mean knowledge scores increased from 65 to 70.5 among Deaf leaders, representing an 8.5% relative increase, and from 51 to 60.6 among hearing mental health professionals, representing a 19.0% relative increase. Among Deaf leaders, reported knowledge of mental health symptoms increased from 58% to 89%, while perceived ability to support Deaf peers increased from 53% to 89%. Among professionals, understanding of Deaf culture increased from 8% to 42%, and awareness of barriers to mental health services increased from 50% to 92%. SRQ-20 screening identified positive screening results for mental health problems in 79% of Deaf participants, while 32% reported suicidal ideation. These findings represent screening results among program participants and not diagnostic or population prevalence estimates. Qualitative findings highlighted four main themes: relevance of the training, the need for interactive and accessible approaches, strengthening communication competence, and the need for continued training and collaboration. Conclusion: The bidirectional training strengthened mental health literacy among Deaf leaders and increased awareness of Deaf culture, communication, and access barriers among mental health professionals. Continued Deaf–professional collaboration and follow-up training may support the development of culturally and linguistically responsive mental health services.