Our SIG focuses on designing technologies that support mental health and well-being. Common mental health disorders like depression and anxiety are leading causes of disability worldwide, yet access to care remains limited. Technologies such as mobile apps, AI tools, and virtual care could help close this treatment gap. However, if not designed with human values like justice, participation, and inclusion in mind, they risk harming individuals. The SIG will explore, test, and refine methods for integrating human values into the design of mental health technologies. We will establish a transformative knowledge hub on designing technology that promotes mental well-being.