Objective: The purpose of this study was to identify strategies for encouraging greater levels of physical activity among community-dwelling individuals living with serious mental illness participating in assertive community treatment (ACT). Method: Eighteen individuals living with serious mental illness participated in focus group interviews. Participants were recruited from an ACT provider located in the Midwestern United States. A semistructured interview protocol was developed specifically for this study. Participants responded to a series of questions on ACT physical activity programming, providing (a) information about their personal experiences with physical activity–related interventions and (b) suggestions for intervention strategies that may enhance physical activity participation in this population. Consensual qualitative research conventions, a qualitative methodology used in social sciences, were followed for organizing, coding, quantifying, and interpreting participant responses. Results: Several unique themes emerged from the data. Participants identified a variety of strategies used by their ACT provider to encourage physical activity, such as group physical activities and incentive programs. A number of recommendations related to skills training, intervention characteristics, and motivational strategies were identified by the participants as well. Conclusions and Implications for Practice: Physical activity is an important part of successful treatment for individuals with serious mental illness. In this study, participants identified a variety of strategies that may be useful for incorporating within the ACT treatment paradigm. Participant responses were frequently consistent with the tenets of popular health behavior theory (e.g., self-determination theory). Future research should focus on the efficacy of the recommended intervention strategies and their implementation within ACT treatment settings. (PsycINFO Database Record (c) 2018 APA, all rights reserved)