<p>Cognitive aging reflects underlying biological aging processes and is a key driver of late-life functional outcomes. Emerging evidence indicates that cohabitation with companion animals may influence multiple systemic pathways involved in cognitive aging, yet this potentially modifiable lifestyle factor remains underrecognized. The present narrative review synthesizes current evidence on how companion animals may influence cognitive aging through multilevel pathways, including both direct biological mechanisms and proximal psychosocial mediators. The reviewed literature suggests that companion animal ownership may counteract cognitive decline through several primary biological pathways, including stress regulation and neuroendocrine buffering, cerebrovascular and metabolic health, neuroplasticity and neuroimmune modulation, and neurovascular aging and vascular cognitive impairment processes. In parallel, companion animals may exert their effects through psychosocial pathways that ultimately operate via biological systems and indirectly affect cognitive aging through intrapersonal emotion regulation, interpersonal social facilitation, behavioral activation, and cognitive stimulation. We further identify possible key moderating factors shaping these associations, including gender, attachment strength, type and number of animals, cultural context, and the presence versus absence of a companion animal. Finally, we provide a concise overview of methodological approaches for assessing cognitive aging within the context of companion animal research. Overall, this perspective highlights possible cognitive benefits that can be associated with companion animal ownership which may arise from a dynamic interplay of biological, psychological, and social processes differentially modulated by individual, relational, and contextual factors.</p>