Low rates of physical activity, in addition to other poor physical health behaviors, contribute to lower quality of life and increased rates of premature mortality for people living with mental illness. Physical activity reduces this mortality gap while simultaneously improving mood, cognitive function, and symptomology for a variety of psychiatric disorders. While physical activity programs are feasible and acceptable in this population, significant barriers exist that limit long-term adherence. Accredited exercise physiologists (AEPs) are best-placed in Australia to lead physical activity interventions for people living with mental illness. Additionally, AEPs provide an important role in improving culture change within mental health settings by influencing clinicians' attitudes to physical activity interventions. Leading international mental health organizations should collaborate and promote the role of physical activity to increase the provision of such services to people living with mental illness.