The concept of planetary health blurs the artificial lines between health at scales of person, place, and planet. It emphasizes the interconnected grand challenges of our time, and underscores the need for integration of biological, psychological, social, and cultural aspects of health in the modern environment. Here, in our Viewpoint article, we revisit vaccine pioneer Jonas Salk’s contention that wisdom is central to the concept of planetary health. Our perspective is centered on the idea that practical wisdom is associated with decision-making that leads to flourishing—the vitality and fullest potential of individuals, communities, and life on the planet as a whole. The SARS-CoV-2 pandemic has illustrated the acute consequences of unwise and mindless leadership; yet, wisdom and mindfulness, or lack thereof, is no less consequential to grotesque biodiversity losses, climate change, environmental degradation, resource depletion, the global burden of non-communicable diseases (NCDs), health inequalities, and social injustices. Since mindfulness is a teachable asset linked to both wisdom and flourishing, we argue that mindfulness deserves much greater attention in the context of planetary health.