Mitochondria, vital organelles within cells, govern energy metabolism. They play a pivotal role in maintaining redox homeostasis and are instrumental in the initiation and transmission of cell death signals, along with the synthesis of biological macromolecules. The role of mitochondria in tumor evolution and treatment has recently been the focus of extensive research. Studies indicate that the quality and biogenesis of mitochondria, along with their structure, functions, and macromolecule synthesis relevant to it, are intimately linked to tumorigenesis and the prognostic outcomes of clinical treatments. As such, therapies targeting mitochondria offer promising avenues to augment the efficacy of tumor treatment. We summarized the inherent links between mitochondrial structure, mitochondrial genes, metabolism of mitochondrial-related biological macromolecules, and mitochondria-regulated cell death in relation to tumorigenesis and progression. Furthermore, we reviewed the latest research progress in targeting mitochondria for tumor therapy. This study suggests that targeting mitochondria could open new avenues for developing tumor therapy.