Physical inactivity is the fourth most important risk factor contributing to global noncommunicable disease (NCD) deaths, occurring in high-, middle-and low-income countries. Building capacity in NCD prevention is a daunting task, and toward this end, an introductory open online course about physical activity (PA), exercise, and NCD prevention was developed. This was led by academics from the University of Sydney and the WHO Collaborating Centre for Physical Activity, Nutrition and Obesity. The course was designed to address the needs of participants from areas where geography and economy would often prevent them from participating in NCD training programs. Around 120 participants from four continents signed up for the six-week online course, with the greatest numbers from the host country (Australia) followed by participants from Pacific Island nations and from the Middle East. The course consisted of video lectures, quizzes, and online discussions facilitated by experts. More than a third of the participants fully completed the course, which received very positive participant evaluations. This also included completion of relevant quiz questions on each section of the PA course, and averaged over 70% correct responses. This successful online course has the potential to increase knowledge and skills about PA and prevention, as part of building global capacity in NCD prevention at low cost, and importantly within easy reach of potentially isolated practitioners.