Health professionals have increasing concern about physical health and wellbeing, as life globally becomes more demanding and stressful, yet people are less active, due to mechanization and automation of work and leisure. Increasing the amount of physical activity (PA) people do is now recognized as a global health priority, but PA continues to decline in many countries. Research on motives for participating in PA shows they have a role in PA promotion. We review theory and research on motives for participation in PA. Then, we describe development and validation of the Physical Activity and Leisure Motivation Scale (PALMS), a 40-item measure that includes eight motives. We report on the international validation of PALMS, showing its robustness to varia-tions in language and culture. We describe the development of a youth version, PALMS-Y, and a broader ver-sion that adds motives related to extreme sports. Next, we discuss PALMS research that has examined differ-ences in primary motives based on gender, age, and type of PA, as well as factorial structure invariance. We then consider studies investigating the influence of psychological variables on the relationship between mo-tives for participation in PA and the amount of PA individuals undertake, including self-efficacy, mindfulness, and passion. To aid in the consistent presentation of PA participation motives, we describe a form of motiva-tional profiling for use in research and practice. Finally, we propose ways that motives for participation in PA can be used in interventions to increase PA participation, by matching individuals’ primary motives to the type of PA associated with those motives in large PA samples, or using techniques, such as imagery, to enhance key motives. This should achieve the aim of enhancing health and psychological wellbeing around the world.