Many individuals, both in the public and within the field of psychology, often perceive aging as a burden that negatively impacts intellectual and mental health. Our present study aims to challenge this notion by identifying the crucial components of positive mental health in later life. These components not only promote positive mental health but also actively contribute to it, even under difficult circumstances. To accomplish this, we first offer a concise review of well-being and mental health models that highlight the psychological aspects of flourishing in late life. We then introduce a psychological competence-based model for positive mental health, which aligns with the concept of positive aging. Subsequently, we present a measurement tool suitable for practical applications. Finally, we provide a comprehensive overview of positive aging, drawing on methodological guidelines and existing research findings concerning sustainable positive mental health in later life. We examine the evidence indicating that psychological resilience (the capacity to adapt and recover from adversity or stress) and competence (skills and abilities to effectively cope with challenges across various life domains) significantly contribute to slowing down biological aging processes. Furthermore, we discuss insights into the relationship between psychological factors and aging derived from research on Blue Zones (regions characterized by a higher proportion of individuals experiencing longer, healthier lives).