As populations age, identifying psychological resources that support healthy aging and preserve physical functioning has become increasingly important. Although meaning in life (MIL) has been associated with better health and well-being, its associations with objective physical health outcomes and the mechanisms underlying these associations remain incompletely understood. This review synthesized recent evidence on the associations of MIL and purpose in life (PIL) with physical health and examined potential underlying mechanisms. Overall, higher MIL and PIL were generally associated with favorable physical health outcomes, including indicators of slower biological aging, better physical functioning and quality of life, and lower mortality risk. However, much of the evidence, particularly for mortality, physical functioning, and biological indicators, was derived from studies assessing PIL, limiting the generalizability of these findings to the broader construct of MIL. Moreover, these associations were heterogeneous and context-dependent, varying across health outcomes and study populations. Behavioral, psychosocial, and biological pathways have been proposed as potential mechanisms underlying these associations, although their interrelationships and causal sequences have not been sufficiently established. To integrate these findings, this review proposes a hypothetical conceptual cascade framework encompassing multiple levels of health, ranging from biological states and subjective health to physical functioning and survival. Taken together, the findings suggest that MIL and PIL may be conceptualized as upstream psychological resources associated with multiple dimensions of physical health. Nevertheless, further research is needed to clarify the underlying mechanisms and causal directions of these associations.