Physical Activity (PA) offers many physical, social, and mental health benefits to autistic individuals, yet participation rates are low compared to those of neurotypical individuals. This systematic review focused on understanding barriers and facilitators impacting PA participation in autistic individuals. Multiple databases were searched comprehensively for studies conforming to inclusion criteria (i.e., participants included autistic individuals, their parents or caregivers, peer-reviewed in English, qualitative and quantitative methodology) and exclusion criteria (i.e., unpublished thesis, dissertation, or reports, or not published in English). Initial searches yielded 3,505 studies of which 47 met criteria for inclusion. Employing the social-ecological framework (Bronfenbrenner, 1979), PA barriers were organized into a) intrapersonal (e.g., sensory sensitivities, boredom, self-image, behavioural challenges, or lack of necessary supervisory support), b) interpersonal (e.g., PA partner absence or parents’ time constraints), c) community and institutional (e.g., inadequate equipment or lack of transportation), and d) public policy (e.g., autism -related stigma). PA facilitators were organized into a) intrapersonal (e.g., reward perception, personal interest in activities, or group activities), b) interpersonal (e.g., parents, siblings, or friends being physically active), c) community and institutional (e.g., availability of PA programs or supportive PA equipment), and d) public policy (e.g., accessible and inclusive policies). Findings can guide policy and program design, encourage interventions promoting PA among autistic individuals, and inform further research directions regarding effective PA interventions.