The essential role of the peroxisome in oxidizing fatty acids, maintaining reactive oxygen species homeostasis and replenishing tricarboxylic acid cycle intermediates is well known. Recent findings have broadened a spectrum of biomolecules that are synthesized and metabolized in peroxisomes. Emergent evidence supports the view that, by releasing various biomolecules known to modulate essential cellular processes, the peroxisome not only operates as an organizing platform for several developmental and differentiation programs but is also actively involved in defining the replicative and chronological age of a eukaryotic cell. The scope of this chapter is to summarize the evidence that the peroxisome defines yeast longevity by operating as a system controller that: (1) modulates levels of non-esterified fatty acids and diacylglycerol; (2) replenishes tricarboxylic acid cycle intermediates destined for mitochondria; and (3) contributes to the synthesis of polyamines. We critically evaluate molecular mechanisms underlying the essential role of peroxisomally produced and metabolized biomolecules in governing cellular aging in yeast.