Peroxiredoxin 3 (PRDX3) is a mitochondrial antioxidant enzyme that plays a significant role in maintaining cellular redox balance and protecting cells from oxidative stress. PRDX3 is known to be upregulated during tumorigenesis and cancer progression. It regulates cellular signaling pathways associated with Matrix Metalloproteinase-1 (MMP-1) expression and activity in breast cancer progression. Silencing PRDX3 inhibits cell migration and invasion in triple-negative breast cancer cell lines, while overexpression promotes these processes, which are important in the metastatic cascade. PRDX3 is crucial in the regulation of mitochondrial homeostasis and macrophage polarization. A deficiency of PRDX3 leads to an increase in mitochondrial superoxide levels and the induction of inflammation. PRDX3 is also a mitochondrial hydrogen peroxide scavenger that protects cancer cells against hypoxia and drug-induced hydrogen peroxide-dependent apoptosis. In addition, PRDX3 plays a protective role against mitochondrial dysfunction by removing mitochondrial reactive oxygen species.