Magnesium is an essential ion in the human body that plays a crucial role in numerous physiological and pathological processes. Magnesium deficiency is common in older adults and is associated with various age-related chronic diseases. This review explores the relationship between magnesium and the hallmarks of aging, including genomic instability, telomere attrition, epigenetic alterations, loss of proteostasis, deregulated nutrient sensing, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, altered intercellular communication, compromised autophagy, dysbiosis, and chronic inflammation. Magnesium deficiency has been linked to excessive generation of inflammatory markers and free radicals, contributing to chronic inflammation. Maintaining optimal magnesium levels throughout life may be a safe and economical strategy for promoting healthy aging. Future studies are needed to further explore this hypothesis.Magnesium is an essential ion in the human body that plays a crucial role in numerous physiological and pathological processes. Magnesium deficiency is common in older adults and is associated with various age-related chronic diseases. This review explores the relationship between magnesium and the hallmarks of aging, including genomic instability, telomere attrition, epigenetic alterations, loss of proteostasis, deregulated nutrient sensing, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, altered intercellular communication, compromised autophagy, dysbiosis, and chronic inflammation. Magnesium deficiency has been linked to excessive generation of inflammatory markers and free radicals, contributing to chronic inflammation. Maintaining optimal magnesium levels throughout life may be a safe and economical strategy for promoting healthy aging. Future studies are needed to further explore this hypothesis.