Mindfulness, rooted in Buddhism, is applied in healthcare and other fields for its impact on well-being, physiology, emotions, and decision-making. This review examines mindfulness theories to assess current knowledge and identify research gaps. Using the search terms “mindfulness” and “theory” in the SCOPUS database, 76 out of 143 articles met the inclusion criteria. The Monitor and Acceptance theory and the Mindfulness to Meaning Theory are most common among 35 theories identified in this review. Mindfulness is associated with memory, childhood attachment, language development, and social context. Individuals have personalized beliefs about mindfulness and act accordingly to enhance well-being and decision-making. Specific practices and training can augment mindfulness, though excessive mindfulness may have negative effects. The trait and state mindfulness, diversity and uni-dimensionality of measures, persistence of the benefits, demographic variations, and cultural relevance are debated in literature. Further research is needed for a comprehensive understanding of the process, practice, persistence of mindfulness, and its impacts. This review synthesizes literature, highlighting theoretical overlaps and gaps. A key limitation is reliance on a single database. Different mindfulness theories help practitioners design interventions, interpret results, and gain actionable insights. By understanding these frameworks, researchers and clinicians can better apply mindfulness in varied contexts.