Positive childhood experiences (PCEs) are increasingly recognized as critical factors that promote resilience, emotional regulation, and flourishing in children, especially in the context of adversity. This narrative review explores the conceptual development, empirical evidence, and theoretical frameworks underpinning the role of PCEs in early childhood development. A critical assessment of the existing literature focuses on how PCEs function as promotive and protective factors and evaluates the strengths and limitations of current measurement tools. Drawing on theories from resilience science, developmental psychopathology, positive psychology, and ecological systems theory, this review highlights the complex, multidimensional nature of PCEs and their interplay with parenting styles, socioeconomic status, and the social drivers of health. Despite compelling evidence that PCEs influence cognitive, emotional, relational, and behavioral outcomes across the lifespan, there is no dedicated validated tool for prospectively measuring PCEs in preverbal or preschool-aged children. This gap limits our ability to design and test interventions to mitigate adverse childhood experiences and to assess their developmental impact in real time and subsequent periods. We conclude that future research should focus on creating culturally sensitive, developmentally appropriate instruments to measure PCEs in early life, essential for advancing equity, optimizing child health, and promoting wellness across diverse populations.