The ecological crisis demands new strategies to rapidly transform our society into a more sustainable one. A growing amount of research points towards the potential of mindfulness to help transform people’s motivations for sustainability. This article reviews 30 years of research in mindfulness and sustainability and disentangles theoretical knowledge from empirical evidence. We identified six leading theoretical links between mindfulness and sustainability which find backing in empirical work: reduced automaticity, enhanced health and subjective well-being, greater connectedness with nature, improved pro-sociality, recognition of intrinsic values and openness to new experiences. Many of the studies involve considerable methodological caveats, most importantly a lack of mindfulness practice indicators and environmental impact measures. To reach the point where policy makers could embrace mindfulness-based policies to promote societal well-being and sustainability, the research must go beyond the present focus on correlative research. The proof of causality posits the greatest challenge for the next decade of research. Inspired by principles from policy evaluation, we propose a research agenda that offers direction for collaborative efforts and innovative interdisciplinary study designs in a logical model: (how) does the practice of mindfulness contribute to individual behaviour change and (how) does this individual change translate into societal change?