Over the past 40 years, physical activity (PA) and public health has been established as a field of study. A robust evidence base has emerged demonstrating that participation in recommended amounts of PA results in a wide array of physical and mental health benefits. This led to the establishment of federal and global PA guidelines and surveillance programs. Strong evidence supports the efficacy of individual-level (e.g., goal setting) and environmental (e.g., policies) interventions to promote PA. There has also been progress in establishing a skilled and diverse workforce to execute the work of PA and public health. Looking forward, major challenges include stemming the obesity and chronic disease epidemics, addressing health inequities, and diversifying the workforce. Given the known benefits of PA and the availability of evidence-based interventions, efforts now must focus on implementing this knowledge to improve population health and reduce inequities through PA.