A high proportion of people are insufficiently physically active. The reasons for this are complex and in part relate to social determinants of health, lifestyle choices, and deleterious environmental conditions like climate change, loss of green and outdoor environments and a concomitant loss of biodiversity. Physiotherapists, and other health professionals, may have a positive impact on these global issues, through the encouragement of active transport, and advocacy to reduce barriers to its uptake and optimize exposure to health-giving outdoor spaces. In this paper, we demonstrate how physiotherapists can promote active transport as a planetary health intervention, and provide insight into the benefits and challenges of this planetary health intervention, with direct implications to physiotherapy practice.