Purpose of the Study: Adults with HIV infection are living into old age. It is critical we investigate positive constructs such as resilience and mastery to determine factors associated with psychological well-being. We examine HIV-related factors, adverse conditions, and psychosocial characteristics that are associated with resilience (the ability to bounce back) and mastery (sense of self-efficacy). Design and Methods: We analyzed 2014 data from the longitudinal study Aging with Pride: National Health, Aging, and Sexuality/Gender Study (NHAS), focusing on a subsample of 335 gay and bisexual older men. Multivariate linear regression was used to identify factors that contributed or detracted from resilience and mastery in the sample recruited from 17 sites from across the United States. Results: Resilience and mastery were independently associated with psychological health-related quality of life. In multivariate analysis, adjusting for demographic characteristics, previous diagnosis of depression was negatively associated with resilience. Time since HIV diagnosis was positively associated with mastery whereas victimization was negatively associated with mastery. Social support and community engagement were positively associated with both resilience and mastery. Implications: Individual and structural-environmental characteristics contributed to resilience and mastery. These findings can be used to develop interventions incorporating an increased understanding of factors that are associated with both resilience and mastery.