OBJECTIVES: Resilience, the ability to bounce back from a stressful situation, is a valuable asset for aiding adults with serious mental illness (SMI) in navigating the recovery process. People with SMI experience stress, including traumatic experiences at disproportionate rates. The purposes of this study were to examine the factor structure, internal reliability, and construct validity of the Brief Resilience Scale (BRS) among adults with SMI living in the community. DESIGN: A cross-sectional survey design was used. Exploratory factor analysis (EFA), confirmatory factor analysis (CFA), and correlational analyses were employed. METHODS: Three hundred fifteen adults with SMI were recruited for two studies (Sample 1, n = 122; Sample 2, n = 193) from three states. All participants completed the BRS along with nearly identical positive psychology- and psychopathology-related measures. RESULTS: EFA revealed the BRS was unidimensional and explained 61.20% of the variance. Results from seven CFA models suggested a bifactor structure for the BRS, which fit the data best. Internal reliability of the BRS was computed to be within acceptable ranges (α = .87, ω = .90). The BRS was positively correlated with measures of positive coping and life satisfaction, providing convergent validity. Divergent validity was supported by negative correlations between the BRS and measures of psychiatric symptoms, succumbing, and self-stigma. CONCLUSIONS: The BRS is a valid measure that can be used by clinical and research professionals to assess levels of resilience in adults with SMI at baseline and across time. PRACTITIONER POINTS: The Brief Resilience Scale (BRS) was developed to measure a person's ability to bounce back from stressful situations. The BRS was examined in adults with serious mental illness living in the community. The BRS presented a bifactor structure measuring resilience (an outcome) and correlated with positive psychology- and psychopathology-related measures. The BRS can be used by practitioners to assess levels of resilience in their clients at baseline and over time to evaluate the effectiveness of therapeutic interventions.