AKI is associated with high morbidity and mortality, and it predisposes to the development and progression of CKD. Novel strategies that minimize AKI and halt the progression of CKD are urgently needed. Normal kidney function involves numerous different cell types, such as tubular epithelial cells, endothelial cells, and podocytes, working in concert. This delicate balance involves many energy-intensive processes. Fatty acids are the preferred energy substrates for the kidney, and defects in fatty acid oxidation and mitochondrial dysfunction are universally involved in diverse causes of AKI and CKD. This review provides an overview of ATP production and energy demands in the kidney and summarizes preclinical and clinical evidence of mitochondrial dysfunction in AKI and CKD. New therapeutic strategies targeting mitochondria protection and cellular bioenergetics are presented, with emphasis on those that have been evaluated in animal models of AKI and CKD. Targeting mitochondrial function and cellular bioenergetics upstream of cellular damage may offer advantages compared with targeting downstream inflammatory and fibrosis processes.