Aging is a complex physiological process characterized by an irreversible decline in tissue and cellular functions, accompanied by an increased risk of age-related diseases, including neurodegenerative, cardiovascular, and metabolic disorders. Central to this process are epigenetic modifications, particularly DNA methylation, which regulate gene expression and contribute to aging-related epigenetic drift. This drift is characterized by global hypomethylation and localized hypermethylation, impacting genomic stability and cellular homeostasis. Simultaneously, mitochondrial dysfunction, a hallmark of aging, manifests as impaired oxidative phosphorylation, excessive reactive oxygen species production, and mitochondrial DNA mutations, driving oxidative stress and cellular senescence. Emerging evidence highlights a bidirectional interplay between epigenetics and mitochondrial function. DNA methylation modulates the expression of nuclear genes governing mitochondrial biogenesis and quality control, while mitochondrial metabolites, such as acetyl-CoA and S-adenosylmethionine, reciprocally influence epigenetic landscapes. This review delves into the intricate nuclear-mitochondrial crosstalk, emphasizing its role in aging-related diseases and exploring therapeutic avenues targeting these interconnected pathways to counteract aging and promote health span extension.