Objectives: Evaluation of physical activity (PA) programs among populations with severe mental illness (SMI) has predominately focused on efficacy and therapeutic benefits. There is now strong evidence to support the benefits of PA in people with SMI. What remains is a gap in the implementation of pragmatic and sustainable PA interventions in mental-health settings. The current paper provides examples of interventions that have been successfully implemented in Australian settings, identifies key components of successful PA interventions and outlines practical strategies that can assist with widespread implementation of PA interventions in mental-health settings. Conclusions: There is an emergence of PA interventions being imbedded within a variety of mental-health settings. These interventions vary in terms of mode and intensity of service delivery. Yet, all aim to increase PA and reduce sedentary behaviour. Adopting the identified strategies may help facilitate successful implementation and increase access to PA interventions for mental-health service users.