In this article, I argue for a novel understanding of compassion—what I call a ‘compassion towards thriving’ approach—to inform public mental health ethics. The argument is developed through two main parts. In the first part, I develop an account of compassion towards thriving that builds upon Martha Nussbaum’s philosophical work on compassion. This account expands the ambit of compassion from a focus on the alleviation of existing suffering to the prevention of potential future suffering through the facilitation of personal growth based on a ‘psychosocial’ understanding of mental health. In the second part of the article, I discuss the aims of public mental health and examine compassion towards thriving’s normative synergies with existing approaches in public health ethics. I explain how compassion towards thriving supports a vision of public health ethics which is concerned with solidarity, social justice and flourishing. I then apply this compassion towards thriving approach to evaluate the ‘Every Mind Matters’ public mental health campaign in England, highlighting its affinities with the ethos of the campaign. I also identify and explain two ways in which the application of a compassion towards thriving approach could enhance its delivery.